Article Seven required nine state ratifications for the U.S. Constitution to take effect.
The Constitution was signed by delegates at the Philadelphia Convention on September 17, 1787, but signing did not make it the operating framework of the United States. Article Seven specified that conventions in nine states had to ratify the document before it became effective among the approving states.
New Hampshire supplied the crucial ninth ratification on June 21, 1788. The new federal government began operating in 1789, with George Washington inaugurated as president on April 30 in New York City. Four states had still not ratified when the Constitution took effect: Virginia, New York, North Carolina, and Rhode Island.
The rule was controversial because the Articles of Confederation required unanimous approval for major changes. Supporters of the Constitution argued that nine states represented a sufficient foundation for a new union, while opponents feared that the arrangement could divide the states. The final state, Rhode Island, ratified in 1790.