Nine states had to ratify the U.S. Constitution before it could take effect in the founding era commemorated by America250.
Article Seven established the Constitution’s ratification rule: approval by conventions in nine states would be sufficient to establish the Constitution among the states that ratified it. This threshold was a compromise between requiring unanimous approval and allowing a small minority to create the new government.
Delaware was first to ratify, on December 7, 1787. The decisive ninth approval came from New Hampshire on June 21, 1788. The Constitution therefore became effective before Virginia, New York, North Carolina, and Rhode Island had ratified it.
The rule is often mistaken for a requirement that all thirteen states approve the Constitution before it could operate. In fact, North Carolina and Rhode Island joined later, and Rhode Island did not ratify until May 29, 1790. Article Seven governed the original Constitution’s launch, not the later amendment process.