Delaware became the first state to ratify the U.S. Constitution, approving it unanimously on December 7, 1787. Its ratifying convention voted 30–0 in favor of the proposed governing framework.
The Constitution had been signed by delegates at the Constitutional Convention in Philadelphia on September 17, 1787. Article Seven required ratification by conventions in the states and specified that approval by nine states would be sufficient for the Constitution to take effect among those states.
Pennsylvania followed Delaware on December 12, while New Jersey ratified on December 18 and Georgia on January 2, 1788. These early approvals helped create momentum, although ratification was closely contested in several larger states.
New Hampshire became the crucial ninth state on June 21, 1788, placing the Constitution into effect. Rhode Island was the last of the original thirteen states to ratify, doing so on May 29, 1790. Delaware’s early unanimous vote earned it the nickname “The First State.”