Nine states had to ratify the U.S. Constitution before it could take effect, a founding milestone relevant to America250.
Article Seven specified that ratification by conventions in nine states would be sufficient to establish the Constitution among the states ratifying it. This threshold was a compromise: requiring all thirteen states could have allowed one or two governments to block the new framework indefinitely.
New Hampshire became the ninth state to ratify on June 21, 1788. Virginia and New York ratified soon afterward, while North Carolina and Rhode Island initially remained outside the new constitutional system. Rhode Island eventually ratified in 1790, becoming the last of the original thirteen states to do so.
The nine-state rule did not mean that every state had ratified when the new government began. It meant the Constitution could legally operate among the states that accepted it. This is different from the unanimous approval associated with the Declaration of Independence and helps explain the separate ratification process after the 1787 convention.