when was the constitution created

The United States Constitution was created during the summer of 1787 in Philadelphia, Pennsylvania, at the Constitutional Convention. It was signed on September 17, 1787, by delegates from 12 states who gathered to replace the Articles of Confederation with a new framework for government. Afterward, it was sent to the states for ratification, which required approval by nine of the thirteen states to become effective. The decisive ninth state, New Hampshire, ratified the Constitution on June 21, 1788, officially making it the governing document of the United States for those states.