Here are some key dates related to the creation of the Constitution:
May 25, 1787: The Constitutional Convention begins in Philadelphia, Pennsylvania. Delegates from 12 of the 13 states (Rhode Island did not send delegates) meet to revise the Articles of Confederation, the governing document of the newly independent United States.
September 17, 1787: The Constitutional Convention completes its work and approves the final draft of the Constitution. The document is signed by 39 of the 55 delegates present.
September 28, 1787: The Constitution is sent to the states for ratification. Each state holds its own ratification convention to vote on whether to accept or reject the Constitution.
June 21, 1788: New Hampshire becomes the ninth state to ratify the Constitution, meeting the requirement for the Constitution to go into effect.
April 30, 1789: George Washington is inaugurated as the first President of the United States under the new Constitution. The new federal government begins operating.
So, while there isn't a single date that marks the creation of the Constitution, these events and dates provide an overview of the process of its development and ratification.