U.S. Constitution, Annotated

Read the Preamble to the Constitution and the associated annotations.

Article V.

AMENDING THE CONSTITUTION

The Congress, whenever two thirds of both Houses shall deem it necessary, shall propose Amendments to this Constitution, or, on the Application of the Legislatures of two thirds of the several States, shall call a Convention for proposing Amendments, which, in either Case, shall be valid to all Intents and Purposes, as Part of this Constitution, when ratified by the Legislatures of three fourths of the several States, or by Conventions in three fourths thereof, as the one or the other Mode of Ratification may be proposed by the Congress; Provided [that no Amendment which may be made prior to the Year One thousand eight hundred and eight shall in any Manner affect the first and fourth Clauses in the Ninth Section of the first Article; and] that no State, without its Consent, shall be deprived of its equal Suffrage in the Senate.

Commentary:  Amendments may be proposed by a two-thirds vote of each house of Congress or by a national convention called by Congress at the request of two-thirds of the states.  To become part of the Constitution, amendments must be ratified (approved) by the legislatures of three-fourths of the states or by conventions in three-fourths of the states.

The framers of the Constitution purposely made it hard to put through an amendment.  Congress has considered more than 9,000 amendments, but it has proposed only 33 and submitted them to the states.  Of these, only 27 have been ratified.  Only one amendment, the 21st, was ratified by state conventions.   All the others were ratified by state legislatures.

The Constitution sets no time limit during which the states must ratify a proposed amendment.  But the courts have held that amendments must be ratified within a "reasonable time" and that Congress decides what is reasonable, as it did when it allowed the promulgation of the 27th Amendment on May 7, 1992 – more than 202 years after it was proposed.  Since the early 1900s, most proposed amendments have included a requirement that the necessary ratification be obtained within seven years.