How is the Constitution amended?

#Two ways to propose an amendment

Article V names two routes. In the first, Congress proposes an amendment when two-thirds of both houses agree. The Supreme Court held in the National Prohibition Cases (1920) that this means two-thirds of the members present, assuming a quorum, and not two-thirds of the whole membership. Congress uses a joint resolution, and it does not go to the White House for signature or approval.

In the second route, the legislatures of two-thirds of the states apply, and Congress “shall call a Convention for proposing Amendments.” As of November 2026, the National Archives says none of the 27 amendments has been proposed this way. A convention’s proposal would still need ratification, because Article V sets the same test “in either Case.”

#Two ways to ratify

Both routes lead to the same second step. Three-fourths of the states, now 38 of 50, must ratify, and Congress chooses whether state legislatures or state conventions decide. Only one amendment has gone through conventions: the Twenty-first, which repealed the Eighteenth. Congress passed it on February 20, 1933, and its text required ratification “by conventions in the several States.” It was ratified on December 5, 1933. The other 26 went through state legislatures.

#Deadlines and limits

The text of Article V sets no deadline. In Dillon v. Gloss (1921), the Supreme Court read it to require ratification “within some reasonable time after the proposal,” and it said Congress may fix a definite period, there seven years. In Coleman v. Miller (1939), the Court’s opinion said Congress, in controlling the promulgation of an amendment, has the final say on whether a proposal lost its vitality with the passage of time.

Article V also has limits of its own. One barred any amendment before 1808 from affecting two clauses of Article I. The other has no end date: “no State, without its Consent, shall be deprived of its equal Suffrage in the Senate.”

#A worked example: the Twenty-seventh Amendment

This amendment says no law changing congressional pay takes effect “until an election of Representatives shall have intervened.” It used the congressional proposal route and the state legislature ratification route.

• September 25, 1789: The First Congress proposes 12 articles. This one is the second, and the resolution’s ratification language names no deadline.
• 1789–1791: Maryland, North Carolina, South Carolina, Delaware, Vermont and Virginia ratify it. Ten other articles are ratified on December 15, 1791, and become the Bill of Rights.
• 1873 and 1978: Ohio ratifies on May 6, 1873, and Wyoming on March 6, 1978.
• 1982–1983: A University of Texas at Austin student, Gregory Watson, writes a paper on the amendment and lobbies state legislatures. Maine ratifies on April 27, 1983.
• May 7, 1992: Michigan and New Jersey ratify, and the House Manual records ratification as complete on this date.
• May 18, 1992: The Archivist of the United States certifies the amendment. The National Archives notes that some members of Congress questioned the legality of an amendment pending for more than 202 years.
• May 20, 1992: The House adopts a concurrent resolution declaring the ratification, and the Senate adopts its own. Neither chamber takes up the other’s.

#Who handles the paperwork

The president has no constitutional role in the process. After Congress proposes an amendment, the Archivist, who heads the National Archives, administers ratification under 1 U.S.C. § 106b. The Office of the Federal Register prepares a package for the states, and the Archivist sends a letter to each governor. Ratifying states send back original or certified copies of their action, and the office checks them for legal sufficiency on their face and for an authenticating signature. Once the required number is in, the Archivist certifies the amendment.