Appendix B: The Bill of Rights and All Subsequent Amendments

How to Read This Appendix

The Constitution as ratified in 1788 has been amended 27 times in 238 years. The first 10 amendments were proposed together and ratified in 1791, three years after the original Constitution went into effect; they are collectively the Bill of Rights. The remaining 17 amendments span 1795 to 1992. Six of the 17 cluster in distinct historical moments: the Reconstruction Amendments (13, 14, 15) following the Civil War, and the Progressive Era Amendments (16, 17, 18, 19) in the 1910s. Most of the rest address discrete institutional questions.

This appendix uses the same format as Appendix A: verbatim text in > blockquote, plain-English translation in italic, annotation in regular text with chapter cross-references.

A note on incorporation. The Bill of Rights, as originally adopted in 1791, applied only to the federal government. In 1833, Barron v. Baltimore held that the Fifth Amendment's Takings Clause did not apply to the states. The Civil War, the 13th, 14th, and 15th Amendments, and (very gradually) the doctrine of selective incorporation changed this. Beginning with Gitlow v. New York (1925), the Supreme Court has applied most of the Bill of Rights to state and local governments through the Due Process Clause of the 14th Amendment. As of 2026, the only Bill of Rights provisions not yet incorporated are the Third Amendment's quartering prohibition (which has never come up), the Seventh Amendment's right to civil jury trial, and the Grand Jury Clause of the Fifth Amendment. Every other provision binds state and local governments as well as the federal government. See Ch. 5 and Ch. 6.

The text of each amendment is the canonical version maintained by the National Archives (archives.gov/founding-docs/amendments).

The Bill of Rights (Amendments 1–10), Ratified December 15, 1791

The Bill of Rights was the price of ratification. Several state ratifying conventions made clear that they would only ratify the Constitution if a Bill of Rights followed; Madison, who had initially opposed the idea (thinking enumerated powers were a sufficient protection), reversed course and shepherded the amendments through the First Congress. Twelve amendments were proposed; 10 were ratified together. (The two that were not ratified at that time: a complex apportionment scheme, never ratified; and a congressional pay limit, ratified 203 years later as the 27th Amendment.)

Amendment I — Speech, Press, Religion, Assembly, Petition

Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.

Plain English: Congress cannot establish an official religion, restrict religious practice, or restrict speech, the press, the right to peaceful assembly, or the right to petition the government.

The First Amendment is the source of five distinct doctrines. Free Exercise — protecting religious practice — has narrowed since Employment Division v. Smith (1990), which held that neutral, generally applicable laws can apply to religious practice; the Religious Freedom Restoration Act (1993) and many state RFRAs have partially restored a higher standard. The Establishment Clause — preventing government endorsement of religion — has been substantially reframed by the Roberts Court (notably in Kennedy v. Bremerton, 2022, which moved away from the Lemon v. Kurtzman test in favor of a "history and tradition" approach). Free Speech doctrine includes content-neutrality requirements, the strict scrutiny standard for content-based restrictions, the categorical exclusion of certain speech (incitement, true threats, defamation, obscenity), and the unsettled status of online platform regulation (Moody v. NetChoice, 2024, partially addressed this; further litigation continues). Freedom of the Press is largely subsumed under free speech doctrine; New York Times v. Sullivan (1964) sets a high bar for libel suits by public officials. Assembly and Petition are less litigated but provide the constitutional foundation for protest rights and lobbying. See Ch. 5 for the doctrinal map; Ch. 18 for press and political communication; Ch. 34 for Citizens United and money as speech.

Amendment II — Right to Bear Arms

A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.

Plain English: Because organized state defense forces are necessary, the people's right to own and carry guns will not be infringed.

The Second Amendment is one of the two amendments where Supreme Court doctrine changed dramatically in the 21st century (the other is the 14th Amendment, after Dobbs). For most of American history, the leading reading of the amendment was the collective-rights view: the right to bear arms is connected to militia service, not to individual self-defense. District of Columbia v. Heller (2008), in a 5–4 decision by Justice Scalia, adopted the individual-rights reading: the prefatory clause about the militia explains the purpose, but the operative clause protects an individual right to keep and bear arms for self-defense. McDonald v. Chicago (2010) incorporated Heller against the states. New York State Rifle and Pistol Association v. Bruen (2022) tightened the doctrinal test: gun regulations must be consistent with "the nation's historical tradition of firearm regulation," a standard that has produced significant lower-court litigation and inconsistent application. The contested current questions involve concealed-carry permitting, prohibitions on certain weapons types, and the application of the historical-tradition test to legislation Congress has not yet enacted (e.g., red-flag laws, certain ammunition restrictions). See Ch. 5.

Amendment III — Quartering of Soldiers

No Soldier shall, in time of peace be quartered in any house, without the consent of the Owner, nor in time of war, but in a manner to be prescribed by law.

Plain English: The government cannot force homeowners to house soldiers in peacetime without consent, or in wartime except as Congress specifies.

The Third Amendment was a response to the British practice, in the colonial period, of forcing colonists to house British troops in private homes. It is the only amendment that has produced essentially zero modern Supreme Court doctrine; the only significant case is Engblom v. Carey (2d Cir. 1982), which involved the displacement of state prison guards by National Guard troops during a strike. The amendment is a useful reminder that not every constitutional provision generates a doctrinal industry. See Ch. 5.

Amendment IV — Search and Seizure

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

Plain English: People are protected from unreasonable government searches and seizures of themselves, their homes, their documents, and their property. Warrants must be supported by probable cause, sworn under oath, and must specifically describe what's being searched and what's being seized.

The Fourth Amendment generates more daily litigation than perhaps any other constitutional provision. The doctrine has two main branches: when does a search require a warrant, and when does a warrantless search require probable cause or some lower standard?

The warrant requirement has many exceptions: consent searches, searches incident to arrest, automobile searches (with probable cause), exigent circumstances, plain view, and others. The reasonable expectation of privacy test from Katz v. United States (1967) has been the dominant framework, but the Roberts Court has revived a property-based reading in cases like United States v. Jones (2012, GPS tracker on car) and Florida v. Jardines (2013, drug-detection dog at home).

Recent doctrinal developments have addressed digital privacy. Riley v. California (2014) held that police generally need a warrant to search the contents of a cellphone seized incident to arrest. Carpenter v. United States (2018) held that the government generally needs a warrant to obtain extended cellphone-location records, departing from the longstanding "third-party doctrine" (no expectation of privacy in information shared with third parties). The application of Fourth Amendment doctrine to digital surveillance, social media, and AI-driven monitoring is among the most active areas of constitutional law. See Ch. 5 and Ch. 38.

Amendment V — Self-Incrimination, Double Jeopardy, Due Process, Takings, Grand Jury

No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a Grand Jury, except in cases arising in the land or naval forces, or in the Militia, when in actual service in time of War or public danger; nor shall any person be subject for the same offence to be twice put in jeopardy of life or limb; nor shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.

Plain English: For serious federal crimes, charges must come from a grand jury (with exceptions for military). No one can be tried twice for the same offense, forced to testify against themselves, or deprived of life, liberty, or property without fair legal process. The government cannot take private property for public use without paying for it.

This amendment packs five distinct rights into one provision:

1. Grand Jury Clause — applies only to federal felonies. Not incorporated against the states.
2. Double Jeopardy Clause — prevents reprosecution for the same offense after acquittal or conviction. (The dual-sovereignty doctrine permits separate state and federal prosecutions; Gamble v. United States, 2019, reaffirmed it.)
3. Self-Incrimination Clause — the foundation for the Fifth Amendment privilege and for Miranda v. Arizona (1966, requiring Miranda warnings before custodial interrogation).
4. Due Process Clause (federal) — protects fundamental procedural and substantive fairness. (The 14th Amendment Due Process Clause applies the same protections against the states, and is more litigated.)
5. Takings Clause — the foundation of eminent domain doctrine. Kelo v. New London (2005), holding that economic-development takings can satisfy the public-use requirement, was politically controversial and produced state-law backlash.

See Ch. 5 for procedural protections and Ch. 14 for substantive due process.

Amendment VI — Rights of the Accused

In all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial, by an impartial jury of the State and district wherein the crime shall have been committed, which district shall have been previously ascertained by law, and to be informed of the nature and cause of the accusation; to be confronted with the witnesses against him; to have compulsory process for obtaining witnesses in his favor, and to have the Assistance of Counsel for his defence.

Plain English: Criminal defendants have the right to a speedy and public jury trial in the location where the crime occurred; the right to know the charges; the right to confront witnesses against them and call witnesses in their defense; and the right to a lawyer.

The Sixth Amendment is the foundation of American criminal procedure for the accused. Gideon v. Wainwright (1963) incorporated the right to counsel against the states in felony cases; Argersinger v. Hamlin (1972) extended it to misdemeanors involving incarceration. The right to confront witnesses, after Crawford v. Washington (2004), has been vigorously enforced. The right to a jury trial in non-capital cases has been substantially eroded in practice by the prevalence of plea bargaining (more than 95% of federal criminal cases end in pleas), though the formal right remains. See Ch. 5.

Amendment VII — Civil Jury Trial

In Suits at common law, where the value in controversy shall exceed twenty dollars, there shall be a right of trial by jury, and no fact tried by a jury, shall be otherwise re-examined in any Court of the United States, than according to the rules of the common law.

Plain English: In federal civil cases worth more than $20, parties have the right to a jury trial. Findings of fact by a jury cannot be re-examined except according to common-law rules.

The Seventh Amendment is the only Bill of Rights provision regularly enforced in federal civil practice that has never been incorporated against the states. (States can — and most do — provide civil jury trials by their own constitutional or statutory choice, but they are not required to by the federal Constitution.) The $20 threshold has not been adjusted for inflation since 1791.

Amendment VIII — Cruel and Unusual Punishment, Excessive Fines and Bail

Excessive bail shall not be required, nor excessive fines imposed, nor cruel and unusual punishments inflicted.

Plain English: Bail and fines cannot be excessive, and punishment cannot be cruel and unusual.

The Cruel and Unusual Punishments Clause has produced two distinct lines of case law: capital-punishment doctrine (the death penalty has been declared unconstitutional for juveniles, the intellectually disabled, and for non-homicide crimes against individuals), and prison-conditions doctrine (the Eighth Amendment limits the conditions of confinement). The Excessive Fines Clause was incorporated against the states in Timbs v. Indiana (2019), which held that civil asset forfeiture can violate the clause. See Ch. 5.

Amendment IX — Unenumerated Rights

The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people.

Plain English: The fact that this Constitution lists specific rights doesn't mean those are the only rights people have. Other rights exist.

The Ninth Amendment is one of the most theoretically interesting and least practically litigated provisions in the Bill of Rights. It addresses the central concern of opponents of the Bill of Rights — that any list of rights would be read as exhaustive — by providing that the listing is not exhaustive. What the unenumerated rights are, and how they would be enforced, the amendment does not say.

The Ninth Amendment was invoked by Justice Goldberg's concurrence in Griswold v. Connecticut (1965, recognizing a right to marital privacy) and has been a subject of ongoing scholarly debate. In modern practice, unenumerated-rights claims are usually brought under the Due Process Clause of the 14th Amendment as substantive due process claims. See Ch. 5 and Ch. 14.

Amendment X — Reserved Powers

The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.

Plain English: Powers not given to the federal government and not denied to the states belong to the states or to the people.

The Tenth Amendment is the textual home of American federalism. For most of the 20th century, the Court read it as a "truism" — restating what was already implicit in the enumerated-powers structure of the original Constitution. New York v. United States (1992) revived the amendment as an enforceable check, holding that Congress cannot "commandeer" state legislatures. Printz v. United States (1997) extended the anti-commandeering principle to state executive officials. NFIB v. Sebelius (2012) used the principle to invalidate the ACA's mandate that states expand Medicaid (holding it amounted to coercion). See Ch. 4.

Amendment XI (Ratified February 7, 1795) — Suits Against States

The Judicial power of the United States shall not be construed to extend to any suit in law or equity, commenced or prosecuted against one of the United States by Citizens of another State, or by Citizens or Subjects of any Foreign State.

Plain English: Federal courts can't hear lawsuits brought against a state by citizens of another state or by foreigners.

The Eleventh Amendment was a direct response to Chisholm v. Georgia (1793), in which the Supreme Court held that a citizen of South Carolina could sue the state of Georgia in federal court — over Georgia's strenuous objection. The decision provoked an immediate constitutional reaction; Congress proposed the amendment within a year, and it was ratified within two.

The amendment has been read by the Court (notably in Hans v. Louisiana, 1890, and Seminole Tribe v. Florida, 1996) to embody a broader principle of state sovereign immunity — states generally cannot be sued in federal court without their consent, even by their own citizens. The doctrine has exceptions (Congress can abrogate sovereign immunity using its 14th Amendment Section 5 power; states can waive immunity; lawsuits against state officials in their personal capacity for prospective injunctive relief are permitted under Ex parte Young, 1908). The breadth of state sovereign immunity is contested, with originalist scholars divided on whether Hans correctly extended the amendment beyond its text.

Amendment XII (Ratified June 15, 1804) — Electoral College Reform

The Electors shall meet in their respective states, and vote by ballot for President and Vice-President, one of whom, at least, shall not be an inhabitant of the same state with themselves; they shall name in their ballots the person voted for as President, and in distinct ballots the person voted for as Vice-President, and they shall make distinct lists of all persons voted for as President, and of all persons voted for as Vice-President, and of the number of votes for each, which lists they shall sign and certify, and transmit sealed to the seat of the government of the United States, directed to the President of the Senate;—the President of the Senate shall, in the presence of the Senate and House of Representatives, open all the certificates and the votes shall then be counted;—The person having the greatest number of votes for President, shall be the President, if such number be a majority of the whole number of Electors appointed; and if no person have such majority, then from the persons having the highest numbers not exceeding three on the list of those voted for as President, the House of Representatives shall choose immediately, by ballot, the President. But in choosing the President, the votes shall be taken by states, the representation from each state having one vote; a quorum for this purpose shall consist of a member or members from two-thirds of the states, and a majority of all the states shall be necessary to a choice. And if the House of Representatives shall not choose a President whenever the right of choice shall devolve upon them, before the fourth day of March next following, then the Vice-President shall act as President, as in the case of the death or other constitutional disability of the President. The person having the greatest number of votes as Vice-President, shall be the Vice-President, if such number be a majority of the whole number of Electors appointed, and if no person have a majority, then from the two highest numbers on the list, the Senate shall choose the Vice-President; a quorum for the purpose shall consist of two-thirds of the whole number of Senators, and a majority of the whole number shall be necessary to a choice. But no person constitutionally ineligible to the office of President shall be eligible to that of Vice-President of the United States.

Plain English: Electors cast separate ballots for president and vice president. The president needs a majority of the Electoral College; if no one wins, the House chooses (with each state delegation getting one vote). The vice president also needs a majority; if no one wins, the Senate chooses. Anyone constitutionally ineligible to be president cannot be vice president.

The Twelfth Amendment fixed a problem the original Constitution's electors-cast-two-ballots procedure had created. In 1796, the Federalist John Adams won the presidency and his political opponent, the Democratic-Republican Thomas Jefferson, won the runner-up vice presidency, an awkward arrangement. In 1800, every Democratic-Republican elector cast both ballots for Jefferson and his running mate Aaron Burr, producing a tie that threw the election into the House of Representatives. The House took 36 ballots before electing Jefferson. The amendment, ratified before the next election, separated the presidential and vice-presidential ballots and produced the modern ticket-based system.

The amendment also created the modern contingent election procedure for the House and Senate. The contingent election has been used twice since 1804: 1824 (the House chose John Quincy Adams over Andrew Jackson, who had won a plurality of both popular and electoral votes), and 1837 (the Senate chose Richard Mentor Johnson as vice president). The procedure is widely considered to be poorly designed for a modern political party system; the one-vote-per-state rule in the House contingent election would heavily favor whichever party controls more state delegations, which may not match the popular vote. See Ch. 22 and Ch. 38.

The Reconstruction Amendments (Amendments 13, 14, 15) — 1865 to 1870

The Reconstruction Amendments are sometimes called the "second founding." They were proposed and ratified in the aftermath of the Civil War, reshaping American constitutional structure to abolish slavery, define national citizenship, and prohibit racial discrimination in voting. Each transferred substantial power from the states to the federal government and established a new constitutional baseline. The 14th Amendment in particular has come to be the most-litigated and most-consequential amendment in U.S. history; most modern civil-rights and civil-liberties law runs through it.

Amendment XIII (Ratified December 6, 1865) — Abolition of Slavery

Section 1. Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction.

Section 2. Congress shall have power to enforce this article by appropriate legislation.

Plain English: Slavery and forced labor are abolished, except as punishment for a crime. Congress has the power to pass laws enforcing this.

The Thirteenth Amendment formally ended chattel slavery in the United States. The Emancipation Proclamation (1863) had freed enslaved persons in Confederate-controlled territory; the amendment extended freedom universally and constitutionalized it.

The "except as a punishment for crime" clause is one of the most consequential textual qualifications in the Constitution. It became, after Reconstruction, the constitutional foundation for convict leasing systems in the postwar South, and it remains the textual basis for the legality of compelled prison labor. The clause has been the focus of recent reform proposals; several states have removed similar exceptions from their state constitutions in the past decade. Amendment to the federal version has been proposed but has not advanced. See Ch. 6 and Ch. 38.

The 13th Amendment is also notable for being the first amendment that contains a congressional enforcement clause — Section 2's grant of power to Congress to "enforce this article by appropriate legislation." The 14th and 15th Amendments contain similar enforcement clauses (Section 5 of the 14th, Section 2 of the 15th). The enforcement clauses are the constitutional foundation for modern civil rights legislation: the Civil Rights Act of 1866 (under the 13th), the Civil Rights Acts of 1964 and 1968 (primarily under the 14th and Commerce Clause), and the Voting Rights Act of 1965 (under the 15th).

Amendment XIV (Ratified July 9, 1868) — Citizenship, Privileges, Due Process, Equal Protection

Section 1. All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.

Section 2. Representatives shall be apportioned among the several States according to their respective numbers, counting the whole number of persons in each State, excluding Indians not taxed. But when the right to vote at any election for the choice of electors for President and Vice President of the United States, Representatives in Congress, the Executive and Judicial officers of a State, or the members of the Legislature thereof, is denied to any of the male inhabitants of such State, being twenty-one years of age, and citizens of the United States, or in any way abridged, except for participation in rebellion, or other crime, the basis of representation therein shall be reduced in the proportion which the number of such male citizens shall bear to the whole number of male citizens twenty-one years of age in such State.

Section 3. No person shall be a Senator or Representative in Congress, or elector of President and Vice President, or hold any office, civil or military, under the United States, or under any State, who, having previously taken an oath, as a member of Congress, or as an officer of the United States, or as a member of any State legislature, or as an executive or judicial officer of any State, to support the Constitution of the United States, shall have engaged in insurrection or rebellion against the same, or given aid or comfort to the enemies thereof. But Congress may by a vote of two-thirds of each House, remove such disability.

Section 4. The validity of the public debt of the United States, authorized by law, including debts incurred for payment of pensions and bounties for services in suppressing insurrection or rebellion, shall not be questioned. But neither the United States nor any State shall assume or pay any debt or obligation incurred in aid of insurrection or rebellion against the United States, or any claim for the loss or emancipation of any slave; but all such debts, obligations and claims shall be held illegal and void.

Section 5. The Congress shall have power to enforce, by appropriate legislation, the provisions of this article.

Plain English: Section 1: Anyone born or naturalized in the U.S. and subject to its jurisdiction is a citizen of both the U.S. and their state of residence. States cannot abridge citizens' privileges or immunities, deny anyone due process or equal protection. Section 2: Representation is apportioned by total population (superseding the three-fifths clause), with a (largely unused) penalty for states that disenfranchise male voters. Section 3: People who took an oath to the Constitution and then engaged in insurrection cannot hold office, unless Congress lifts the disability by two-thirds vote. Section 4: The federal debt is valid; Confederate debts and slaveholder compensation claims are not. Section 5: Congress can enforce this amendment.

The Fourteenth Amendment is the most consequential addition to the Constitution since the original Bill of Rights. Section 1 contains four distinct clauses, each generative of an enormous body of doctrine.

The Citizenship Clause ("All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens"). This clause overruled the Dred Scott decision (1857), which had held that Black Americans, free or enslaved, could never be U.S. citizens. The clause established birthright citizenship as a constitutional principle: virtually anyone born on U.S. soil is a U.S. citizen. United States v. Wong Kim Ark (1898) confirmed that the clause extends to children of non-citizen immigrants. The scope of the "subject to the jurisdiction thereof" qualification is sometimes argued to permit narrower readings, but the long-settled view (applied by every administration since 1898) is that it excludes only children of foreign diplomats, members of an invading foreign army, and (until 1924, when statutory citizenship was extended to them) members of Native American tribes recognized as sovereign. As of 2026, executive proposals to read the clause more narrowly are in active litigation; the doctrinal status is contested. See Ch. 6 and Ch. 31.

The Privileges or Immunities Clause ("No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States"). This clause was eviscerated almost immediately by The Slaughter-House Cases (1873), which read it to protect only a narrow set of national-citizenship rights (e.g., the right to travel between states, the right to access federal courts), while leaving most fundamental rights protection to state law. Many constitutional scholars across the ideological spectrum think Slaughter-House was wrongly decided, and there have been periodic efforts to revive the clause. McDonald v. Chicago (2010) saw a vigorous concurrence by Justice Thomas arguing for revival; the majority chose to incorporate the Second Amendment through Due Process instead. The Privileges or Immunities Clause is the great unrealized provision of the post-Civil-War Constitution. See Ch. 6 and Ch. 14.

The Due Process Clause ("nor shall any State deprive any person of life, liberty, or property, without due process of law"). The 14th Amendment Due Process Clause has produced two distinct doctrines:

• Procedural due process — the requirement that government action affecting life, liberty, or property follow fair procedures (notice, opportunity to be heard, neutral decisionmaker).
• Substantive due process — the doctrine that "liberty" includes substantive rights, and that some government action infringing those rights is unconstitutional regardless of procedure. This is the most contested doctrine in modern constitutional law. It was the basis for Lochner v. New York (1905, striking down maximum-hours laws on freedom-of-contract grounds), which the Court repudiated in 1937. It returned in Griswold v. Connecticut (1965, contraception) and Roe v. Wade (1973, abortion). Lawrence v. Texas (2003) and Obergefell v. Hodges (2015) extended substantive due process to consensual sexual relationships and same-sex marriage. Dobbs v. Jackson Women's Health Organization (2022) overruled Roe and Casey, with the majority opinion casting doubt on the entire substantive-due-process framework. The current scope of substantive due process is contested; see Ch. 5 and Ch. 14.

The Equal Protection Clause ("nor deny to any person within its jurisdiction the equal protection of the laws"). The Equal Protection Clause is the constitutional foundation for the modern law of discrimination. Doctrine has developed three tiers of scrutiny:

• Strict scrutiny for racial classifications and certain other suspect classes — the government must show a compelling interest narrowly tailored. Brown v. Board of Education (1954) is the canonical case; Loving v. Virginia (1967) struck down anti-miscegenation laws; Students for Fair Admissions v. Harvard (2023) struck down race-conscious college admissions.
• Intermediate scrutiny for sex classifications and certain others. Craig v. Boren (1976) and United States v. Virginia (1996) are the canonical cases.
• Rational basis for everything else, with occasional exceptions ("rational basis with bite") for classifications motivated by animus.

See Ch. 6 and Ch. 14.

Section 3 — the Insurrection Disqualification Clause — was largely dormant for more than a century after the Civil War. It returned to constitutional litigation after the events of January 6, 2021. Trump v. Anderson (2024) held that states cannot enforce Section 3 against federal candidates without congressional implementing legislation; the question of how Section 3 is enforced against federal officeholders remains contested. Congress has not enacted enforcement legislation. See Ch. 37 and Ch. 38.

The other sections are less litigated: Section 2's representation-reduction penalty has never been enforced; Section 4's public-debt provision was invoked rhetorically in debt-ceiling debates of the 2010s and 2020s; Section 5 is the textual basis for federal civil-rights legislation, with the scope of the enforcement power contested in City of Boerne v. Flores (1997) and Shelby County v. Holder (2013).

Amendment XV (Ratified February 3, 1870) — Right to Vote (Race)

Section 1. The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of race, color, or previous condition of servitude.

Section 2. The Congress shall have power to enforce this article by appropriate legislation.

Plain English: Voting cannot be denied or abridged based on race or prior enslaved status. Congress can enforce this.

The Fifteenth Amendment prohibited racial discrimination in voting. It did not, in practice, secure Black voting rights — Southern states adopted poll taxes, literacy tests, white primaries, grandfather clauses, and outright violence to suppress Black voting through most of the period from 1890 to 1965. The Voting Rights Act of 1965 was the federal statute that finally produced effective enforcement; Shelby County v. Holder (2013) struck down the act's preclearance coverage formula, with consequences contested between proponents and critics of post-2013 voting changes. See Ch. 6, Ch. 22, and Ch. 36.

The Progressive Era Amendments (Amendments 16–19) — 1913 to 1920

The Progressive Era produced a cluster of amendments addressing income inequality, the structure of the Senate, alcohol policy, and women's suffrage. The four amendments span seven years and reflect the political coalitions of the era.

Amendment XVI (Ratified February 3, 1913) — Income Tax

The Congress shall have power to lay and collect taxes on incomes, from whatever source derived, without apportionment among the several States, and without regard to any census or enumeration.

Plain English: Congress can levy income taxes without apportioning the burden among states by population.

The Sixteenth Amendment was a direct response to Pollock v. Farmers' Loan & Trust Co. (1895), which had held that an income tax on income from property was a "direct tax" subject to the apportionment requirement of Article I, Section 9 (which would have made a federal income tax practically unworkable). The amendment removed the apportionment requirement specifically for income taxation, enabling the modern federal income tax — and, by extension, the modern federal welfare state. See Ch. 16.

Amendment XVII (Ratified April 8, 1913) — Direct Election of Senators

The Senate of the United States shall be composed of two Senators from each State, elected by the people thereof, for six years; and each Senator shall have one vote. The electors in each State shall have the qualifications requisite for electors of the most numerous branch of the State legislatures.

When vacancies happen in the representation of any State in the Senate, the executive authority of such State shall issue writs of election to fill such vacancies: Provided, That the legislature of any State may empower the executive thereof to make temporary appointments until the people fill the vacancies by election as the legislature may direct.

This amendment shall not be so construed as to affect the election or term of any Senator chosen before it becomes valid as part of the Constitution.

Plain English: Senators are elected directly by the voters of each state, not by state legislatures (as originally provided in Article I, Section 3). Vacancies are filled by special election, with the option for governors to make temporary appointments.

The Seventeenth Amendment was the culmination of decades of reform pressure, driven by repeated Senate-deadlocked state legislatures (which sometimes left Senate seats vacant for months or years), allegations of bribery in Senate elections, and progressive ideological commitments to direct democracy. Some originalist scholars argue that direct election has weakened the federal system by removing the structural representation of state governments in Congress. The argument is contested and the amendment has not been the subject of serious repeal proposals. See Ch. 7 and Ch. 38.

Amendment XVIII (Ratified January 16, 1919) — Prohibition

Section 1. After one year from the ratification of this article the manufacture, sale, or transportation of intoxicating liquors within, the importation thereof into, or the exportation thereof from the United States and all territory subject to the jurisdiction thereof for beverage purposes is hereby prohibited.

Section 2. The Congress and the several States shall have concurrent power to enforce this article by appropriate legislation.

Section 3. This article shall be inoperative unless it shall have been ratified as an amendment to the Constitution by the legislatures of the several States, as provided in the Constitution, within seven years from the date of the submission hereof to the States by the Congress.

Plain English: One year after ratification, the manufacture, sale, transportation, import, or export of alcoholic beverages is prohibited throughout the U.S. Congress and the states share enforcement power. The amendment must be ratified within 7 years.

The Eighteenth Amendment imposed national alcohol Prohibition. It went into effect in January 1920. Prohibition is widely regarded as the most spectacular policy failure in American constitutional history: it produced a massive black market, fueled organized crime, was widely flouted, and was repealed by the 21st Amendment in 1933 — the only constitutional amendment ever to be repealed by another. The Eighteenth Amendment is also the only amendment to have included an explicit time limit (Section 3), a feature that became standard for subsequent amendments.

Amendment XIX (Ratified August 18, 1920) — Women's Suffrage

The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of sex.

Congress shall have power to enforce this article by appropriate legislation.

Plain English: Voting cannot be denied or abridged based on sex. Congress can enforce this.

The Nineteenth Amendment guaranteed women the constitutional right to vote, capping a 72-year movement that began with the 1848 Seneca Falls Convention. By the time the amendment was ratified, several states already permitted women to vote (Wyoming was first in 1869). The amendment did not, in practice, fully enfranchise all American women — Black women in the South faced the same Jim Crow voting barriers as Black men until the 1965 Voting Rights Act. See Ch. 6 and Ch. 36.

Amendment XX (Ratified January 23, 1933) — Lame Duck Amendment

Section 1. The terms of the President and the Vice President shall end at noon on the 20th day of January, and the terms of Senators and Representatives at noon on the 3d day of January, of the years in which such terms would have ended if this article had not been ratified; and the terms of their successors shall then begin.

Section 2. The Congress shall assemble at least once in every year, and such meeting shall begin at noon on the 3d day of January, unless they shall by law appoint a different day.

Section 3. If, at the time fixed for the beginning of the term of the President, the President elect shall have died, the Vice President elect shall become President. If a President shall not have been chosen before the time fixed for the beginning of his term, or if the President elect shall have failed to qualify, then the Vice President elect shall act as President until a President shall have qualified; and the Congress may by law provide for the case wherein neither a President elect nor a Vice President elect shall have qualified, declaring who shall then act as President, or the manner in which one who is to act shall be selected, and such person shall act accordingly until a President or Vice President shall have qualified.

Section 4. The Congress may by law provide for the case of the death of any of the persons from whom the House of Representatives may choose a President whenever the right of choice shall have devolved upon them, and of the case of the death of any of the persons from whom the Senate may choose a Vice President whenever the right of choice shall have devolved upon them.

Section 5. Sections 1 and 2 shall take effect on the 15th day of October following the ratification of this article.

Section 6. This article shall be inoperative unless it shall have been ratified as an amendment to the Constitution by the legislatures of three-fourths of the several States within seven years from the date of its submission.

Plain English: Presidential and vice-presidential terms end at noon on January 20. Congressional terms end at noon on January 3. Congress meets annually starting January 3. If the president-elect dies or cannot serve, the vice president-elect becomes (or acts as) president. The amendment self-destructs if not ratified within 7 years.

The Twentieth Amendment shortened the "lame duck" period between presidential elections (held in November) and inauguration (originally March 4). The four-month gap had been a holdover from a constitutional design that assumed slow communication and travel; by the 20th century it was an unworkable interval, especially during transitions in crisis (the Hoover-to-FDR transition during the depths of the Great Depression was a particularly visible example). The amendment moved presidential inauguration to January 20 and congressional terms to January 3.

Amendment XXI (Ratified December 5, 1933) — Repeal of Prohibition

Section 1. The eighteenth article of amendment to the Constitution of the United States is hereby repealed.

Section 2. The transportation or importation into any State, Territory, or possession of the United States for delivery or use therein of intoxicating liquors, in violation of the laws thereof, is hereby prohibited.

Section 3. This article shall be inoperative unless it shall have been ratified as an amendment to the Constitution by conventions in the several States, as provided in the Constitution, within seven years from the date of the submission hereof to the States by the Congress.

Plain English: The 18th Amendment (Prohibition) is repealed. States can still prohibit alcohol within their own borders; importing alcohol into a "dry" state for use there is forbidden. The amendment must be ratified within 7 years, by state conventions (not legislatures).

The Twenty-First Amendment is doubly distinctive. It is the only amendment to repeal an earlier amendment (the 18th), and it is the only amendment to be ratified by state conventions rather than state legislatures. The convention path was chosen because Prohibition advocates dominated many state legislatures, while polls and the 1932 election had made clear that public opinion had decisively turned against Prohibition; the conventions were a way to bypass the legislature and let voters speak through delegates elected for the single purpose of voting on repeal.

Section 2 has produced a small body of doctrine permitting states to maintain "dry" status (still relevant in some local-option counties) and broader debates about state regulation of interstate alcohol commerce. Granholm v. Heald (2005) struck down state laws favoring in-state wineries over out-of-state ones; Tennessee Wine and Spirits Retailers Association v. Thomas (2019) struck down a state residency requirement for liquor licenses.

Amendment XXII (Ratified February 27, 1951) — Two-Term Limit

Section 1. No person shall be elected to the office of the President more than twice, and no person who has held the office of President, or acted as President, for more than two years of a term to which some other person was elected President shall be elected to the office of the President more than once. But this Article shall not apply to any person holding the office of President when this Article was proposed by the Congress, and shall not prevent any person who may be holding the office of President, or acting as President, during the term within which this Article becomes operative from holding the office of President or acting as President during the remainder of such term.

Section 2. This article shall be inoperative unless it shall have been ratified as an amendment to the Constitution by the legislatures of three-fourths of the several States within seven years from the date of its submission to the States by the Congress.

Plain English: No one can be elected president more than twice. Anyone who served more than 2 years of someone else's term as president can only be elected once.

The Twenty-Second Amendment constitutionalized the two-term tradition begun by George Washington and observed by every president until Franklin Roosevelt, who won four terms (1932, 1936, 1940, 1944). After FDR's death in 1945, the Republican-controlled Congress proposed the amendment in 1947; it was ratified in 1951.

The amendment applies only to election; a vice president who succeeds to the presidency mid-term and serves less than 2 years can still be elected twice (potentially totaling almost 10 years in office). Lyndon Johnson served 14 months of Kennedy's term, then was elected in 1964; under the amendment, he could have been elected in 1968 (he chose not to run). Whether the amendment should be repealed has been periodically debated; no proposal has gained significant traction. See Ch. 9 and Ch. 38.

Amendment XXIII (Ratified March 29, 1961) — DC Electoral Votes

Section 1. The District constituting the seat of Government of the United States shall appoint in such manner as the Congress may direct:

A number of electors of President and Vice President equal to the whole number of Senators and Representatives in Congress to which the District would be entitled if it were a State, but in no event more than the least populous State; they shall be in addition to those appointed by the States, but they shall be considered, for the purposes of the election of President and Vice President, to be electors appointed by a State; and they shall meet in the District and perform such duties as provided by the twelfth article of amendment.

Section 2. The Congress shall have power to enforce this article by appropriate legislation.

Plain English: Washington DC gets electors for president, equal to the number of senators and representatives it would have if it were a state, but not more than the least populous state has. (In practice: 3 electoral votes.)

The Twenty-Third Amendment gave Washington, D.C., representation in the Electoral College — but not voting representation in Congress. As of 2026, DC residents continue to have no voting representation in the Senate or House (one non-voting delegate in the House); D.C. statehood proposals (which would address the larger representation issue) have not advanced through the Senate. See Ch. 38.

Amendment XXIV (Ratified January 23, 1964) — Poll Tax Ban

Section 1. The right of citizens of the United States to vote in any primary or other election for President or Vice President, for electors for President or Vice President, or for Senator or Representative in Congress, shall not be denied or abridged by the United States or any State by reason of failure to pay any poll tax or other tax.

Section 2. The Congress shall have power to enforce this article by appropriate legislation.

Plain English: Voting in federal elections cannot be conditioned on paying a poll tax or any other tax.

The Twenty-Fourth Amendment banned poll taxes in federal elections. Two years later, the Supreme Court extended the prohibition to state elections under the Equal Protection Clause in Harper v. Virginia Board of Elections (1966).

Poll taxes were one of several mechanisms (literacy tests, white primaries, grandfather clauses, residence requirements) that Southern states used to suppress Black voting from the post-Reconstruction era through the 1965 Voting Rights Act. The 24th Amendment, the Harper decision, the Voting Rights Act, and the long-running litigation that followed are all part of the constitutional history of voting rights. See Ch. 6, Ch. 22, and Ch. 36.

Amendment XXV (Ratified February 10, 1967) — Presidential Succession and Disability

Section 1. In case of the removal of the President from office or of his death or resignation, the Vice President shall become President.

Section 2. Whenever there is a vacancy in the office of the Vice President, the President shall nominate a Vice President who shall take office upon confirmation by a majority vote of both Houses of Congress.

Section 3. Whenever the President transmits to the President pro tempore of the Senate and the Speaker of the House of Representatives his written declaration that he is unable to discharge the powers and duties of his office, and until he transmits to them a written declaration to the contrary, such powers and duties shall be discharged by the Vice President as Acting President.

Section 4. Whenever the Vice President and a majority of either the principal officers of the executive departments or of such other body as Congress may by law provide, transmit to the President pro tempore of the Senate and the Speaker of the House of Representatives their written declaration that the President is unable to discharge the powers and duties of his office, the Vice President shall immediately assume the powers and duties of the office as Acting President.

Thereafter, when the President transmits to the President pro tempore of the Senate and the Speaker of the House of Representatives his written declaration that no inability exists, he shall resume the powers and duties of his office unless the Vice President and a majority of either the principal officers of the executive department or of such other body as Congress may by law provide, transmit within four days to the President pro tempore of the Senate and the Speaker of the House of Representatives their written declaration that the President is unable to discharge the powers and duties of his office. Thereupon Congress shall decide the issue, assembling within forty-eight hours for that purpose if not in session. If the Congress, within twenty-one days after receipt of the latter written declaration, or, if Congress is not in session, within twenty-one days after Congress is required to assemble, determines by two-thirds vote of both Houses that the President is unable to discharge the powers and duties of his office, the Vice President shall continue to discharge the same as Acting President; otherwise, the President shall resume the powers and duties of his office.

Plain English: Section 1: If the president is removed, dies, or resigns, the vice president becomes president. Section 2: A vice-presidential vacancy is filled by presidential nomination, confirmed by majority vote in both houses of Congress. Section 3: The president can voluntarily transfer power to the vice president (as Acting President) and resume it at will. Section 4: The vice president and a majority of the cabinet (or other body Congress designates) can declare the president incapacitated; the president can dispute it; if they do, two-thirds of both houses of Congress must agree the president is incapacitated, or the president resumes office.

The Twenty-Fifth Amendment fills gaps left by the original Constitution's brief succession language. The amendment was prompted in significant part by the Kennedy assassination (1963), which left Lyndon Johnson as president without a vice president for the rest of the term. (Johnson's medical history of heart disease made the absence particularly worrying.) The amendment was proposed in 1965 and ratified two years later.

The amendment has been used several times since 1967:

• Section 2 has been invoked twice. Gerald Ford was nominated by Nixon and confirmed by Congress as vice president in 1973, after Spiro Agnew resigned. Nelson Rockefeller was nominated by Ford and confirmed by Congress in 1974, after Ford himself succeeded Nixon.
• Section 3 has been invoked at least four times for medical procedures: once by Reagan (1985, before colon surgery, though the formal invocation was disputed), twice by George W. Bush (2002 and 2007, both for colonoscopies), and once by Biden (2021, also for a colonoscopy).
• Section 4 has never been formally invoked. There were reported discussions of Section 4 invocation during the Reagan administration (after the 1981 assassination attempt and during late-term cognitive concerns), and again in early 2021 (after January 6), but no Section 4 declaration has been made.

The procedural complexity of Section 4 reflects the seriousness of declaring a president incapacitated against the president's wishes. The two-thirds-of-both-houses standard for sustaining such a declaration is, by design, almost as high a bar as conviction in an impeachment trial.

See Ch. 9 and Ch. 10.

Amendment XXVI (Ratified July 1, 1971) — 18-Year-Old Vote

Section 1. The right of citizens of the United States, who are eighteen years of age or older, to vote shall not be denied or abridged by the United States or by any State on account of age.

Section 2. The Congress shall have power to enforce this article by appropriate legislation.

Plain English: Citizens 18 and older cannot have their voting rights denied or abridged on account of age. Congress can enforce this.

The Twenty-Sixth Amendment lowered the federal voting age to 18. The amendment was the fastest-ratified amendment in U.S. history, completing the process in three months and seven days. The political pressure was supplied by the Vietnam War: 18-year-olds were being drafted to fight, but in most states could not vote until 21. The slogan "old enough to fight, old enough to vote" captured the political case. Congress had attempted to lower the voting age statutorily in 1970; Oregon v. Mitchell (1970) held that Congress could lower the age for federal elections but not state elections, prompting the constitutional amendment to resolve the inconsistency.

Amendment XXVII (Ratified May 7, 1992) — Congressional Pay

No law, varying the compensation for the services of the Senators and Representatives, shall take effect, until an election of Representatives shall have intervened.

Plain English: A law changing congressional pay can't take effect until after the next House election.

The Twenty-Seventh Amendment has the strangest history of any amendment. It was originally proposed by James Madison as part of the Bill of Rights, in September 1789. Six states ratified it in 1789–91 (along with the rest of what became the Bill of Rights), but it failed to reach the three-quarters threshold and was forgotten. It had no time limit (the practice of including time limits was a 20th-century innovation), so it remained technically pending.

In 1982, a University of Texas at Austin sophomore named Gregory Watson wrote a paper for a government class arguing that the amendment could still be ratified. He received a C on the paper. Watson then began lobbying state legislatures to ratify it. State after state did so over the next decade. On May 7, 1992, Michigan became the 38th state to ratify, and the amendment became part of the Constitution — 202 years, 7 months, and 12 days after Madison proposed it.

The amendment's practical effect is modest: it prevents Congress from voting itself an immediate raise. Pay-raise increases must wait until after the next House election. The amendment's deeper significance is in what it demonstrated about the constitutional amendment process: a proposal pending for two centuries can become law, on the initiative of a single college student.

See Ch. 38.

Amendments That Did Not Make It

Many constitutional amendments have been proposed by Congress (or by a sufficient number of states for a convention call) and have failed to be ratified. A few of the most consequential:

The Equal Rights Amendment (ERA). Proposed by Congress in 1972, it states: "Equality of rights under the law shall not be denied or abridged by the United States or by any State on account of sex." The amendment was ratified by 35 states by the original 1979 deadline, three short of the three-quarters threshold. Congress extended the deadline to 1982; no additional states ratified within that period. Several states purported to rescind their prior ratifications (the legal effect is contested). Three additional states (Nevada in 2017, Illinois in 2018, Virginia in 2020) ratified after the extended deadline, bringing the total to 38 — but the deadline issue and the rescission issue have left the amendment's status genuinely unresolved as of 2026. The Archivist of the United States has declined to certify the amendment as ratified; litigation has been unsuccessful. The conceptual case for the ERA is that the Equal Protection Clause's intermediate-scrutiny standard for sex classifications is a weaker protection than strict scrutiny, and an explicit textual guarantee would be stronger; the case against argues that the existing doctrine adequately protects sex equality and that the ERA could be read more expansively (e.g., to require government funding of abortion or to invalidate single-sex spaces). See Ch. 6 and Ch. 38.

The Balanced Budget Amendment. Various versions have been proposed; one came within one Senate vote of the two-thirds requirement in 1995. Versions typically require federal expenditures to not exceed federal revenues except in specified emergencies. Proponents argue it would impose fiscal discipline that ordinary politics cannot; opponents argue it would be unenforceable, would cripple counter-cyclical fiscal policy, and would risk constitutionalizing economic policy choices. See Ch. 16 and Ch. 38.

Term Limits for Members of Congress. Multiple proposals have been advanced, none has reached the two-thirds congressional threshold. The Supreme Court held in U.S. Term Limits v. Thornton (1995) that states cannot impose term limits on their members of Congress through state law; only a federal constitutional amendment can. The proposal has bipartisan support in polls but has not advanced in Congress (likely because incumbents are not inclined to limit themselves). See Ch. 38.

DC Voting Representation Amendment. Proposed by Congress in 1978, would have given DC voting representation in Congress equal to a state's. It was ratified by only 16 of the required 38 states by the 1985 deadline. DC representation has since been pursued primarily through statehood proposals rather than constitutional amendment. See Ch. 38.

Flag Burning Amendment. Proposed multiple times (1989, 1990, 1995, 1997, 1999, 2000, 2003, 2005, 2006), most recently failing in the Senate by one vote in 2006. The amendment would have authorized Congress to prohibit flag desecration, overruling Texas v. Johnson (1989) and United States v. Eichman (1990), which held flag burning to be protected speech. The proposal has not been reintroduced in recent Congresses but remains a live cultural debate. See Ch. 5.

The list is much longer; thousands of amendments have been proposed in Congress over the past two centuries, the great majority of which have not been seriously considered. The high bar for amendment — two-thirds of each chamber and three-quarters of states — is, by design, hard to clear. Whether the bar is too high (foreclosing necessary updates to a 19th-century document) or about right (requiring deep consensus before changing the constitutional baseline) is a recurring debate. See Ch. 38.

The text of all 27 amendments is the canonical version maintained by the National Archives at archives.gov/founding-docs/amendments-11-27. The original Constitution appears in Appendix A. The Declaration of Independence appears in Appendix C.