Delaware was the first state to ratify the U.S. Constitution, approving it on December 7, 1787.
The Delaware convention voted unanimously, with all 30 delegates supporting ratification. This earned Delaware the nickname “The First State,” a title still used today. Its early approval gave the new Constitution an important opening victory, although the document would not take effect until nine states had ratified it.
Pennsylvania followed on December 12, 1787, and New Jersey became the third state to ratify on December 18. The remaining states debated the Constitution for months, with especially intense disagreements in Massachusetts, Virginia, and New York.
Delaware’s ratification came shortly after the Constitutional Convention in Philadelphia completed its work in September 1787. The Constitution replaced the weaker Articles of Confederation with a federal system featuring separate legislative, executive, and judicial branches. Delaware’s unanimous vote helped begin the formal process that created the United States government still operating today.