New Hampshire became the ninth state to ratify the United States Constitution on June 21, 1788.
Article VII stated that ratification by nine states would be sufficient to establish the Constitution among the states ratifying it. New Hampshire’s approval therefore reached the required threshold, although several important states had not yet voted. Virginia ratified four days later, and New York followed in July.
The New Hampshire convention initially postponed a decision, then reconvened and approved the Constitution by a vote of 57 to 47. North Carolina and Rhode Island remained outside the new constitutional union for a longer period; Rhode Island became the final original state to ratify in 1790.
Reaching nine ratifications did not mean every state immediately joined the new system. It meant the constitutional government could begin for the participating states, with Congress organizing operations in 1789.