Congress must pass a proposed amendment by a two-thirds majority vote in both the Senate and the House of Representatives and send it to the states for ratification by a vote of the state legislatures. ... This process has been used for ratification of every amendment to the Constitution thus far.

What was the purpose of the ratification process?

The ratifying conventions served the necessary function of informing the public of the provisions of the proposed new government. They also served as forums for proponents and opponents to articulate their ideas before the citizenry. Significantly, state conventions, not Congress, were the agents of ratification.

What happened during the ratification?

Three months later, on September 17, 1787, the Convention concluded with the signing (by 38 out of 41 delegates present) of the new U.S. Constitution. ... Under Article VII, it was agreed that the document would not be binding until its ratification by nine of the 13 existing states.