Delaware was the first state to ratify the United States Constitution.
Delaware’s ratifying convention approved the Constitution unanimously on December 7, 1787. Its delegates voted 30–0, earning the state the later nickname “The First State.” Pennsylvania ratified five days afterward, followed by New Jersey and Georgia.
Article Seven required ratification by conventions in at least nine states for the Constitution to take effect. New Hampshire became the ninth state to ratify, on June 21, 1788, putting the Constitution into operation.
Delaware’s early approval did not mean every state accepted the document quickly. Rhode Island, the thirteenth and final state to ratify, did not approve it until May 29, 1790. The ratification sequence is distinct from the Constitutional Convention itself, which had signed the proposed document in Philadelphia in September 1787.