A constitutional amendment is a formal change to the text of the Constitution. Under Article V, adding one to the U.S. Constitution takes two steps: a proposal approved by two-thirds of both houses of Congress (or by a convention called at the request of two-thirds of the state legislatures), followed by ratification by three-fourths of the states. The bar is deliberately high, which is why the Constitution has been amended only 27 times since 1788.
What Amendments Actually Do
Most amendments do one of three things. They create new rights, change how the government operates, or undo an earlier amendment.
The Bill of Rights, ratified in 1791, is the clearest example of the first. Those ten amendments guaranteed liberties like freedom of speech, freedom of the press, and protection against unreasonable searches that the original text did not spell out.1National Archives. The Bill of Rights: What Does it Say? Later rights amendments expanded on that foundation: the Thirteenth abolished slavery, the Nineteenth guaranteed women the right to vote, and the Twenty-sixth lowered the voting age to eighteen.
Structural amendments reshape the mechanics of government. The Twenty-second, ratified in 1951, caps any person at two presidential elections.2Congress.gov. U.S. Constitution – Twenty-Second Amendment The Seventeenth moved Senate elections from state legislatures to a direct popular vote.
The rarest kind is a repealing amendment. The Twenty-first is the only one in U.S. history that erased a prior amendment outright, ending the nationwide alcohol ban imposed by the Eighteenth.3Constitution Annotated. Amdt21.S1.1 Overview of Twenty-First Amendment, Repeal of Prohibition
How an Amendment Gets Proposed in Congress
The common path starts on Capitol Hill. Both the House and Senate must pass a joint resolution by a two-thirds vote. That threshold is based on the members present and voting, assuming a quorum, not on the full membership of each chamber.4Constitution Annotated. ArtV.1 Overview of Article V, Amending the Constitution With vacancies or absences, fewer than 290 House votes or 67 Senate votes can suffice. Every amendment ratified so far has come through this route.
The president has no role. A proposed amendment does not go to the White House for signature or veto. Once both chambers clear the two-thirds bar, the joint resolution goes directly to the National Archives.5National Archives. Constitutional Amendment Process
The Convention Route
Article V also lets the states force the issue. If two-thirds of state legislatures (currently 34 of 50) apply to Congress, Congress must call a convention to propose amendments.6Constitution Annotated. ArtV.3.3 Proposals of Amendments by Convention It has never happened. The closest call came in the early 1900s, when 33 states applied for a convention to propose direct election of senators — one state short. That pressure helped push Congress to propose the Seventeenth Amendment on its own.7Congress.gov. The Article V Convention for Proposing Constitutional Amendments
Because no convention has ever been triggered, basic questions remain unanswered: whether Congress could limit its scope, how delegates would be chosen, and what voting rules would apply.
How Ratification Works
Proposing is only half the work. Ratification requires approval from three-fourths of the states, currently 38 out of 50.5National Archives. Constitutional Amendment Process Congress decides in the joint resolution whether state legislatures or specially called state conventions will cast the ratification votes. Every amendment except the Twenty-first has been ratified by state legislatures; the repeal of Prohibition was the only use of the convention method.8Constitution Annotated. Amdt21.S3.1 Ratification Deadline, State Ratifying Conventions, and the Twenty-First Amendment
An amendment becomes part of the Constitution the moment the thirty-eighth state ratifies it. The Archivist’s later certification is a ministerial step that formally announces the change, but the legal force kicks in at ratification.5National Archives. Constitutional Amendment Process Federal law requires the Archivist to publish the amendment with a certificate identifying the ratifying states, and the notice appears in the Federal Register and the United States Statutes at Large.9Office of the Law Revision Counsel. 1 USC 106b – Amendments to Constitution
Ratification Deadlines
Article V says nothing about how long states have to ratify. The Supreme Court held in Dillon v. Gloss (1921) that Congress has authority to set a deadline, and starting with the Eighteenth Amendment, Congress has typically included a seven-year window either in the amendment text or in the proposing clause of the joint resolution.10Constitution Annotated. ArtV.4.2.1 Congressional Deadlines for Ratification of an Amendment
Without a deadline, a proposal can linger. The Twenty-seventh Amendment, which bars Congress from giving itself a mid-term pay raise, was proposed in 1789 alongside the Bill of Rights and did not receive its thirty-eighth ratification until 1992 — a gap of more than 202 years.11National Archives. A Record-Setting Amendment
Deadlines have real teeth. The Equal Rights Amendment, proposed in 1972 with a seven-year window, fell three states short by its 1979 deadline. Congress extended the window to 1982, but the amendment stalled at 35 ratifications. Three more states ratified after 2017, but the Justice Department’s Office of Legal Counsel concluded that the original deadline could not be retroactively erased by a later Congress.
Limits on What Can Be Amended
Article V is not entirely open-ended. One permanent restriction remains in its text: no state can be deprived of its equal representation in the Senate without that state’s consent.12Congress.gov. ArtV.5 Unamendable Subjects Even a perfectly executed amendment with two-thirds of Congress and three-fourths of the states behind it could not strip Wyoming of its two Senate seats unless Wyoming agreed.
Two other restrictions existed in the original text but expired in 1808. They protected Congress’s power over the slave trade and certain tax rules from amendment during the country’s first two decades.12Congress.gov. ArtV.5 Unamendable Subjects Those limits no longer apply.
Can a State Take Back Its Vote?
Whether a state can rescind its ratification after voting yes is one of the murkiest questions in constitutional law. The issue surfaced during ratification of the Fourteenth Amendment in 1868, when two states tried to withdraw their approval. Congress counted their ratifications anyway and declared the amendment adopted.13Constitution Annotated. ArtV.4.2.2 Effect of Prior Rejection of an Amendment or Rescission of Ratification
The Supreme Court addressed the question in Coleman v. Miller (1939), calling the validity of ratification a political question for Congress to resolve rather than a legal one for the courts. At least one lower court has disagreed, reasoning that a state should be able to rescind before the three-fourths threshold is reached. No court has definitively settled the point, and the practical answer may turn on whether Congress accepts or rejects a withdrawal when the moment arrives.13Constitution Annotated. ArtV.4.2.2 Effect of Prior Rejection of an Amendment or Rescission of Ratification
Why So Few Amendments Succeed
Congress has sent 33 proposed amendments to the states. Only 27 made it through ratification. The six that failed include some ambitious proposals:14Constitution Annotated. Intro.6.7 Proposed Amendments Not Ratified by the States
- The Congressional Apportionment Amendment (1789), which would have tied the size of the House to population growth by formula. It was proposed alongside the Bill of Rights and never reached enough states.
- The Titles of Nobility Amendment (1810), which would have stripped citizenship from anyone who accepted a foreign title of honor without congressional consent.
- The Child Labor Amendment (1924), which would have given Congress power to regulate labor by anyone under eighteen. Federal child labor laws eventually reached similar ground through the commerce power instead.
- The Equal Rights Amendment (1972), which would have prohibited denial of rights based on sex. It fell short of the ratification deadline, and its status remains contested.
- The D.C. Voting Rights Amendment (1978), which would have given the District of Columbia full congressional representation and a role in the amendment process as if it were a state. It expired in 1985 with 16 state ratifications.
The difficulty is the design. The framers built Article V to ensure that only changes with deep, sustained, nationwide support become part of the country’s highest law. A proposal that cannot clear two-thirds of Congress and three-fourths of the states probably does not command the kind of consensus the founders believed fundamental law requires.