Delaware was the first state to ratify the United States Constitution, doing so on December 7, 1787.
Delaware’s ratifying convention met in Dover and approved the Constitution unanimously, with all 30 delegates voting in favor. Its early approval earned Delaware the nickname “The First State.”
The Constitution required approval from conventions in at least nine states before it could take effect. Delaware’s vote was therefore an important early step, but it did not alone make the Constitution operative. New Hampshire became the ninth state to ratify, on June 21, 1788.
Delaware is sometimes confused with Pennsylvania or New Jersey because both ratified soon afterward. Pennsylvania approved the Constitution on December 12, 1787, while New Jersey followed on December 18. America’s 250th-anniversary observances look back to this ratification era, when the new national government was being established.