United States Constitution:Article VII
For the full text of the U.S. Constitution, see Full Text of the United States Constitution.
Article VII of the United States Constitution explains the Constitution's ratification.
The Ratification of the Conventions of nine States, shall be sufficient for the Establishment of this Constitution between the States so ratifying the Same.
Article VII specifies that 9 of 13 original states had to ratify the Constitution before it would take effect. New Hampshire became the ninth state to ratify the Constitution on June 21, 1788.