Delaware was the first state to ratify the U.S. Constitution, doing so on December 7, 1787.
The state’s ratifying convention met at Dover and approved the Constitution unanimously, with all 30 delegates voting in favor. Delaware’s speed helped give the new federal framework an early boost after the Constitutional Convention submitted it to the states.
Article VII required nine states to ratify the Constitution before it could take effect. New Hampshire became the ninth state on June 21, 1788, while Rhode Island was the last of the original 13 states to ratify, on May 29, 1790.
Delaware is sometimes called “the First State” because of this early ratification. Pennsylvania and New Jersey followed Delaware in December 1787, but neither acted first. The sequence matters because ratification was a state-by-state process rather than a single nationwide vote.