New Hampshire supplied the ninth ratification that put the United States Constitution into effect in 1788.
New Hampshire’s convention approved the Constitution on June 21, 1788, by a vote of 57 to 47. Article Seven specified that ratification by nine of the 13 states would be sufficient to establish the Constitution among the states ratifying it.
The decision was a turning point because the required threshold had been reached. Virginia ratified four days later, and New York followed in July. North Carolina and Rhode Island held out longer, but their delays did not stop the new constitutional system from being organized.
New Hampshire was the ninth state in the ratification sequence, not the ninth state admitted to the Union. That distinction matters because the original 13 states were already former British colonies and founding members of the United States. Rhode Island ultimately became the thirteenth and final state to ratify.