Which state was the first to ratify the U.S. Constitution?

Delaware was the first state to ratify the U.S. Constitution.

Delaware’s ratifying convention approved the Constitution unanimously on December 7, 1787. Its early approval earned the state the nickname “The First State,” still used today. The vote took place in Dover, then the state capital.

Article VII stated that the Constitution would become effective after nine states ratified it. Delaware was followed by Pennsylvania, New Jersey, Georgia, and Connecticut. New Hampshire became the ninth state on June 21, 1788, putting the new federal system into operation.

A common mix-up is confusing the first ratifying state with the last of the original thirteen. Rhode Island was the last, ratifying on May 29, 1790. Delaware’s vote came nearly two and a half years earlier, before George Washington’s presidency began under the Constitution.