26 September 1947 – The United States Air Force became a separate military service on 18 September 1947 with the implementation of the National Security Act of 1947.
The Army Air Forces were abolished by Transfer Order 1, Office of the Secretary of Defense, 26 September 1947, implementing the same provisions. Transfer Order 1 was the first of 200 Army-Air Force transfer agreements drawn up in June and July 1947 and ordered the transfer of all military and civilian personnel of the Army Air Forces to the Department of the Air Force and the USAF. The final transfer order was signed on 22 June 1949.