Sept. 17 (UPI) -- On this date in history: In 1787, the U.S. Constitution, completed in Philadelphia, was signed by a majority of the 55 delegates to the Constitutional Convention. Nine states ratified the document in June 1788, and it became the supreme law of the United States on March 4, 1789. In 1862, Union forces led by Gen. George McClellan attacked Confederate troops led by Gen. Robert E. Lee near Antietam Creek in Maryland. McClellan blocked Lee's advance on Washington but fell short of