For America250’s constitutional history, nine states had to ratify the Constitution for it to take effect.
Article VII established a threshold of nine out of the thirteen states, rather than requiring unanimous approval. This procedure differed from the Articles of Confederation, whose amendment process required approval from every state.
New Hampshire became the ninth state to ratify the Constitution on June 21, 1788. That vote placed the new governmental framework into effect for the ratifying states, although the first federal government did not begin operating until 1789.
Delaware was the first state to ratify, on December 7, 1787. Rhode Island was the last of the original thirteen states, approving the Constitution on May 29, 1790. The nine-state requirement is therefore both a constitutional rule and a key turning point in the transition from the Articles.