The United States Constitution has been amended 27 times since it was ratified in 1788. The 27 amendments to the U.S. Constitution include the ten in the Bill of Rights, three passed after the Civil War, four from the Progressive Era, and a mix of later changes covering voting rights, presidential succession, and congressional pay. Article V sets the process: an amendment can be proposed by a two-thirds vote in both chambers of Congress or by a convention called at the request of two-thirds of the state legislatures, and three-fourths of the states must then ratify it.1Constitution Annotated. U.S. Constitution Article V Every amendment so far has come through Congress; the convention route has never been used.2Constitution Annotated. Proposals of Amendments by Convention
The Bill of Rights (Amendments 1–10)
The first ten amendments were ratified together on December 15, 1791. Several states had refused to ratify the Constitution without a promise that these protections would follow.3National Archives. The Bill of Rights: A Transcription They don’t so much grant rights as draw lines the government cannot cross.
The First Amendment bars the government from establishing a religion, interfering with religious practice, suppressing speech or the press, or punishing peaceful assembly and petition. The Second Amendment protects the right to keep and bear arms, tied in the original text to a well-regulated militia. The Third Amendment prohibits the government from quartering soldiers in private homes during peacetime.
The Fourth Amendment requires warrants based on probable cause before law enforcement can search a person or their property. The Fifth Amendment protects the accused in several ways: it requires a grand jury indictment for serious federal offenses, bars double jeopardy, prohibits forced self-incrimination, and guarantees that no one loses life, liberty, or property without due process. The Sixth Amendment guarantees a speedy public trial before an impartial jury, the right to confront witnesses, and the right to a lawyer.
The Seventh Amendment preserves the right to a jury trial in federal civil cases where more than twenty dollars is at stake, a threshold set in 1791 that has never been adjusted.4Constitution Annotated. U.S. Constitution – Seventh Amendment The Eighth Amendment bans excessive bail, excessive fines, and cruel and unusual punishment. Courts judge whether a fine is excessive by asking whether it is grossly disproportionate to the offense.5Constitution Annotated. Excessive Fines
The Ninth Amendment clarifies that listing certain rights in the Constitution doesn’t mean people lack others. The Tenth Amendment reserves any power not given to the federal government to the states or the people.
Do These Rights Apply to State Governments?
Mostly, yes, but not automatically. In 1833, the Supreme Court ruled in Barron v. Baltimore that the Bill of Rights limited only the federal government.6Justia Law. Barron v. Mayor and City Council of Baltimore, 32 U.S. 243 After the Fourteenth Amendment was ratified in 1868, the Court used its Due Process Clause to apply most Bill of Rights protections against the states one at a time, a case-by-case process called selective incorporation.7Legal Information Institute. Incorporation Doctrine Today nearly every provision binds state and local governments. The exceptions are the Third Amendment, the Seventh Amendment’s civil jury right, the Fifth Amendment’s grand jury requirement, and a narrow Sixth Amendment provision about jury composition.
Early Structural Fixes (Amendments 11–12)
The Eleventh Amendment, ratified in 1795, blocks federal courts from hearing lawsuits filed against a state by citizens of another state or by foreign nationals unless the state consents.8Constitution Annotated. Eleventh Amendment – Suits Against States
The Twelfth Amendment, ratified in 1804, fixed a flaw in presidential elections. Under the original system, each elector cast two votes for president; the runner-up became vice president. When Thomas Jefferson and Aaron Burr tied in 1800, the election went to the House for a bitter fight.9United States Senate. The Senate Elects a Vice President The Twelfth Amendment requires electors to cast separate ballots for president and vice president.10Constitution Annotated. U.S. Constitution – Twelfth Amendment
The Reconstruction Amendments (13–15)
The Civil War produced the biggest changes to the Constitution since its founding.
The Thirteenth Amendment, ratified in 1865, abolished slavery and involuntary servitude, with a single exception for forced labor imposed as criminal punishment after a conviction.11Congress.gov. Constitution of the United States – Thirteenth Amendment
The Fourteenth Amendment, ratified in 1868, did several things at once. It established birthright citizenship for anyone born in the United States and subject to its jurisdiction, and it barred states from denying due process or equal protection.12Constitution Annotated. Fourteenth Amendment Those two clauses have generated more litigation than almost any other constitutional language, producing landmark rulings on civil rights, privacy, marriage equality, and discrimination. Section 3, less well known but recently prominent, bars anyone who took an oath to support the Constitution and then engaged in insurrection from holding federal or state office; Congress can lift the disqualification only by a two-thirds vote of both chambers.13Constitution Annotated. Fourteenth Amendment Section 3 – Disqualification from Holding Office
The Fifteenth Amendment, ratified in 1870, prohibited denying the right to vote based on race, color, or previous condition of servitude.14Constitution Annotated. U.S. Constitution – Fifteenth Amendment Many states spent the next century using literacy tests, grandfather clauses, and poll taxes to suppress Black voters, and enforcement required decades of further legislation.
Progressive Era Reforms (Amendments 16–19)
The Sixteenth Amendment, ratified in 1913, authorized Congress to collect an income tax without dividing the revenue among the states by population.15National Archives. 16th Amendment to the U.S. Constitution: Federal Income Tax (1913) The income tax remains the federal government’s primary revenue source.
The Seventeenth Amendment, also ratified in 1913, moved the election of U.S. senators from state legislatures to the voters directly.16Constitution Annotated. U.S. Constitution – Seventeenth Amendment The old system had produced corruption, deadlocks, and long Senate vacancies.
The Eighteenth Amendment, ratified in 1919, banned the manufacture, sale, and transportation of alcoholic beverages.17Congress.gov. U.S. Constitution – Eighteenth Amendment National Prohibition proved difficult to enforce and lasted roughly thirteen years.
The Nineteenth Amendment, ratified in 1920, guaranteed that the right to vote could not be denied on account of sex.18Constitution Annotated. U.S. Constitution – Nineteenth Amendment It roughly doubled the eligible electorate.
Modernizing Government Operations (Amendments 20–22)
The Twentieth Amendment, ratified in 1933, moved the presidential inauguration from March 4 to January 20 and set the start of new congressional terms at January 3.19Constitution Annotated. Twentieth Amendment The change shortened the lame-duck period between an election and the new administration taking office.
The Twenty-First Amendment, also ratified in 1933, repealed Prohibition. It is the only amendment ever used to undo another and returned the power to regulate alcohol to the states, which is why liquor laws still vary so widely.20Constitution Annotated. U.S. Constitution – Twenty-First Amendment
The Twenty-Second Amendment, ratified in 1951, limits presidents to two elected terms. It was a direct response to Franklin D. Roosevelt’s four consecutive election wins between 1932 and 1944.21FDR Presidential Library. Franklin D. Roosevelt’s Presidency A vice president who takes over and serves two years or less of the predecessor’s term can still run twice on their own, allowing up to about ten years in office.22Constitution Annotated. U.S. Constitution – Twenty-Second Amendment
Expanding the Right to Vote (Amendments 23, 24, and 26)
The Twenty-Third Amendment, ratified in 1961, gave residents of the District of Columbia a vote in presidential elections. The District receives a number of electoral votes equal to what it would have as a state, capped at the least populous state’s total, which in practice means three.23Constitution Annotated. U.S. Constitution – Twenty-Third Amendment
The Twenty-Fourth Amendment, ratified in 1964, abolished poll taxes in federal elections. Those taxes had been used for decades, particularly in the South, to keep low-income and Black voters from the ballot box.
The Twenty-Sixth Amendment, ratified in 1971, lowered the voting age from twenty-one to eighteen.24Constitution Annotated. Ratification of the Twenty-Sixth Amendment The argument was straightforward: if eighteen-year-olds could be drafted to fight in Vietnam, they deserved a vote. Ratification took about one hundred days, faster than any other amendment.25Smithsonian National Museum of American History. The Twenty-Sixth Amendment, 1971
Presidential Succession and Disability (Amendment 25)
The Twenty-Fifth Amendment, ratified in 1967, filled gaps the original Constitution left about presidential succession. Section 1 confirms the vice president becomes president (not merely acting president) if the president dies, resigns, or is removed. Section 2 lets the president nominate a new vice president when the office is vacant, subject to majority approval by both chambers of Congress. That mechanism was used twice in the 1970s when Spiro Agnew and then Richard Nixon left office.
Sections 3 and 4 cover disability. Under Section 3, a president can voluntarily transfer power to the vice president by written declaration to Congress, which has happened during medical procedures. Section 4 addresses the harder case: if the vice president and a majority of the Cabinet declare the president unable to perform the job, the vice president becomes acting president. If the president contests it, Congress has twenty-one days to resolve the dispute, and keeping the vice president in the acting role requires a two-thirds vote of both the House and Senate.26Constitution Annotated. Overview of Twenty-Fifth Amendment, Presidential Vacancy and Disability
Congressional Pay (Amendment 27)
The Twenty-Seventh Amendment has the strangest history of any provision in the Constitution. It was originally proposed in 1789, alongside what became the Bill of Rights, and sat unratified for over two hundred years before a college student’s research paper revived interest in it. It was finally ratified on May 7, 1992.27Constitution Annotated. Ratification of the Twenty-Seventh Amendment The rule itself is simple: any law changing congressional pay cannot take effect until after the next election of Representatives. Members cannot vote themselves an immediate raise; voters get a chance to weigh in first.