The U.S. Constitution has been amended 27 times since it was ratified in 1788. The first ten arrived together as the Bill of Rights in 1791; the other seventeen were added one by one over the next two centuries, changing who can vote, how the government runs, and what rights the states must respect. The 27 amendments to the Constitution fall into a few clear groups, and the summaries below take them in that order rather than strictly by number.
The Bill of Rights (Amendments 1–10)
Ratified in 1791, the first ten amendments were the condition several states set for approving the Constitution at all. They restrict what the federal government can do to individuals.
The First Amendment protects religious freedom, free speech, freedom of the press, peaceful assembly, and the right to petition the government.1Congress.gov. Constitution of the United States – First Amendment The protections are broad but not absolute. Speech intended to incite imminent illegal action, credible threats of violence, and defamation fall outside its coverage.
The Second Amendment protects the right to keep and bear arms.2Congress.gov. Constitution of the United States – Second Amendment
The Third Amendment bars the government from housing soldiers in private homes during peacetime without the owner’s consent.3Congress.gov. Constitution of the United States – Third Amendment
The Fourth Amendment prohibits unreasonable searches and seizures and generally requires a warrant backed by probable cause before the government searches your person or property.4Congress.gov. Constitution of the United States – Fourth Amendment
The Fifth Amendment packs several protections into one provision: grand jury indictment for serious federal crimes, protection against double jeopardy, the right against forced self-incrimination, due process before the government takes life, liberty, or property, and just compensation when property is taken for public use.5Congress.gov. Constitution of the United States – Fifth Amendment
The Sixth Amendment guarantees a speedy, public trial by an impartial jury in criminal cases, along with the right to know the charges, confront witnesses, and have a lawyer.6Congress.gov. Constitution of the United States – Sixth Amendment
The Seventh Amendment preserves the right to a jury trial in federal civil cases where the amount in dispute exceeds twenty dollars. That 1791 threshold has never been adjusted.7Congress.gov. Constitution of the United States – Seventh Amendment
The Eighth Amendment prohibits excessive bail, excessive fines, and cruel and unusual punishment.8Congress.gov. Constitution of the United States – Eighth Amendment
The Ninth Amendment makes clear that the rights listed in the Constitution are not the only rights people have.9Congress.gov. Constitution of the United States – Ninth Amendment
The Tenth Amendment reserves to the states, or to the people, any powers not granted to the federal government.10Congress.gov. Constitution of the United States – Tenth Amendment
One thing to keep in mind: as originally written, the Bill of Rights restricted only the federal government. Most of its protections now apply to state and local governments too, but by way of the Fourteenth Amendment, discussed below.
The Reconstruction Amendments (13, 14, 15)
Three amendments passed after the Civil War redefined citizenship and the government’s obligations to individuals.
The Thirteenth Amendment (1865) abolished slavery and involuntary servitude, with one exception: they may still be imposed as punishment for a crime after conviction.11Congress.gov. Constitution of the United States – Thirteenth Amendment
The Fourteenth Amendment (1868) does several things at once. It establishes birthright citizenship for anyone born or naturalized in the United States and subject to its jurisdiction, and it bars states from denying any person equal protection of the laws or depriving anyone of life, liberty, or property without due process.12Congress.gov. Constitution of the United States – Fourteenth Amendment The Supreme Court has read the citizenship clause to cover children born on U.S. soil even when their parents were not eligible for naturalization, with narrow exceptions for children of foreign diplomats and of enemy forces during a hostile occupation.13Congress.gov. Citizenship Clause Doctrine Over more than a century of case law, the Court has also used this amendment’s Due Process Clause to apply most Bill of Rights protections against state and local governments.14Congress.gov. Overview of Incorporation of the Bill of Rights
The Fifteenth Amendment (1870) prohibits denying the right to vote based on race, color, or previous condition of servitude.15Congress.gov. Constitution of the United States – Fifteenth Amendment States found ways around it for nearly a century through literacy tests, poll taxes, and other devices, but it laid the constitutional foundation later civil rights legislation would build on.
Voting Rights Amendments (19, 23, 24, 26)
Four more amendments expanded the electorate.
The Nineteenth Amendment (1920) prohibits denying the right to vote on account of sex.16Congress.gov. Constitution of the United States – Nineteenth Amendment
The Twenty-third Amendment (1961) gives residents of Washington, D.C., the right to vote in presidential elections by granting the District electoral votes, capped at the number held by the least populous state.17Congress.gov. Constitution of the United States – Twenty-Third Amendment
The Twenty-fourth Amendment (1964) bans poll taxes in federal elections.18Congress.gov. Constitution of the United States – Twenty-Fourth Amendment
The Twenty-sixth Amendment (1971) lowered the voting age from twenty-one to eighteen.19Congress.gov. Constitution of the United States – Twenty-Sixth Amendment
Structural Amendments (11, 12, 16, 17, 20, 22, 25, 27)
Eight amendments have adjusted how the federal government itself operates.
The Eleventh Amendment (1795) restricts federal courts from hearing lawsuits brought against a state by citizens of another state or a foreign country. It remains the foundation of state sovereign immunity in federal court.20Congress.gov. Constitution of the United States – Eleventh Amendment
The Twelfth Amendment (1804) requires electors to cast separate votes for president and vice president. It replaced the original system, under which the runner-up became vice president, after the 1800 election left Thomas Jefferson and his own running mate Aaron Burr tied at 73 electoral votes each and forced the House to decide the outcome over thirty-six ballots.21Congress.gov. Constitution of the United States – Twelfth Amendment
The Sixteenth Amendment (1913) authorizes Congress to collect a federal income tax without apportioning it among the states based on population.22Congress.gov. Constitution of the United States – Sixteenth Amendment
The Seventeenth Amendment (1913) took the power to choose U.S. senators away from state legislatures and gave it to voters directly. It also lets state legislatures authorize the governor to appoint a temporary senator to fill a vacancy until a special election.23Congress.gov. Constitution of the United States – Seventeenth Amendment
The Twentieth Amendment (1933), often called the Lame Duck Amendment, moved the presidential inauguration from March 4 to January 20 and set the start of congressional terms at January 3, shrinking the gap between Election Day and the start of new terms.24Legal Information Institute. 20th Amendment
The Twenty-second Amendment (1951) limits presidents to two elected terms. A person who has served more than two years of someone else’s term can be elected only once on their own.25Congress.gov. Constitution of the United States – Twenty-Second Amendment
The Twenty-fifth Amendment (1967) covers presidential succession and disability. Section 1 confirms that the vice president becomes president when the office is vacated. Section 2 lets the president nominate a new vice president, subject to majority confirmation in both chambers of Congress. Section 3 permits the president to voluntarily transfer power during temporary incapacity. Section 4 lets the vice president and a majority of the cabinet declare the president unable to serve, transferring power to the vice president as acting president.26Congress.gov. Constitution of the United States – Twenty-Fifth Amendment If the president disputes that declaration, Congress decides, and it takes a two-thirds vote in both chambers to keep the vice president in charge.27Constitution Annotated. Overview of Twenty-Fifth Amendment, Presidential Vacancy and Disability
The Twenty-seventh Amendment (1992) prevents any change to congressional pay from taking effect until after the next House election. It was originally proposed in 1789 as part of the package that became the Bill of Rights but was not ratified by the required number of states until 1992, a gap of more than 202 years.28Congress.gov. Constitution of the United States – Twenty-Seventh Amendment
Prohibition and Its Repeal (18, 21)
The Eighteenth Amendment (1920) banned the manufacture, sale, and transportation of alcoholic beverages. It is the only amendment that attempted to regulate personal social behavior through constitutional law, and it took effect on January 17, 1920.29Congress.gov. Constitution of the United States – Eighteenth Amendment30Congress.gov. Overview of Eighteenth Amendment, Prohibition of Liquor
The Twenty-first Amendment (1933) repealed the Eighteenth after nearly fourteen years and returned the power to regulate alcohol to the states, which is why liquor laws still vary so widely today. It is the only amendment ever used to repeal a previous one, and the only one ratified through state conventions rather than state legislatures.31Constitution Annotated. Overview of Twenty-First Amendment, Repeal of Prohibition
How an Amendment Gets Added
Article V of the Constitution sets out two paths for proposing an amendment. The common one requires a two-thirds vote in both the House and the Senate. The alternative is a convention called by two-thirds of state legislatures, which has never been used successfully.32Congress.gov. Article V – Amending the Constitution
Once proposed, an amendment must be ratified by three-fourths of the states. Congress chooses whether ratification happens through state legislatures or through specially called state conventions. Only the Twenty-first was ratified by conventions.32Congress.gov. Article V – Amending the Constitution
The Constitution itself sets no deadline, but the Supreme Court held in Dillon v. Gloss (1921) that Congress can impose a reasonable one. Beginning with the Eighteenth Amendment, Congress has typically attached a seven-year window.33Legal Information Institute. Congressional Deadlines for Ratification of an Amendment Of more than 11,000 amendment proposals introduced in Congress, only these 27 have cleared both stages.