Delaware was the first U.S. state to ratify the Constitution, approving it on December 7, 1787.
Delaware’s ratifying convention accepted the Constitution unanimously, with a recorded vote of 30–0. Pennsylvania followed five days later, and New Jersey became the third state to ratify. Delaware’s early approval earned it the enduring nickname “The First State.”
Article Seven of the Constitution required ratification by nine of the thirteen states for the new government to take effect among the ratifying states. New Hampshire became the ninth state on June 21, 1788, while Rhode Island was the last of the original thirteen states to ratify, on May 29, 1790.
The nickname can cause a small historical mix-up: Delaware was not the first colony to be founded or the first state to declare independence. Its “first” specifically refers to the order in which the states ratified the United States Constitution. Delaware had also ratified the Articles of Confederation later than many other states.