The United States Armed Forces. It is one of the eight U.S.
uniformed services. Initially formed as a part of the United
States Army on 1 August 1907, the USAF was established
as a separate branch of the U.S. Armed Forces on 18 Sep.
1947 with the passing of the National Security Act of 1947.
The Air Force is the second youngest branch of the U.S.
Armed Forces and the fourth in order of precedence.