What year was the U.S. Constitution operational?

The U.S. Constitution became operational in 1788, when it was ratified by the necessary number of states to take effect. The Constitution was drafted during the Constitutional Convention in Philadelphia in 1787 and sent to the states for ratification. The ratification process involved each state debating whether to adopt the Constitution, and it required nine out of thirteen states to agree for the Constitution to be enacted. By June 1788, New Hampshire became the ninth state to ratify the document, enabling it to come into effect. The Constitution was later officially put into operation on March 4, 1789, when the first Congress under its authority convened, but it was ratified and thus considered operational by 1788.