Delaware was the first state to ratify the United States Constitution.
Delaware's ratifying convention approved the Constitution unanimously on December 7, 1787. Its position earned the state the enduring nickname “The First State,” later reinforced by its early support for independence and the Union. The vote came less than three months after the Constitutional Convention signed the proposed document.
Article Seven specified that the Constitution would take effect among the ratifying states once nine states approved it. Delaware's action was therefore symbolically important but did not alone activate the new government. New Hampshire became the ninth state on June 21, 1788, while North Carolina and Rhode Island ratified later.
Delaware's unanimous vote is also a useful contrast with several closely divided conventions, including those in Massachusetts, Virginia, and New York. Ratification unfolded state by state rather than through one nationwide referendum, making the sequence a significant part of the Constitution's founding story.