found:Ravenstein, Charles A. The organization and lineage of the United States Air Force, 1986:pages 1-3 (On August 1, 1907, the United States Army Signal Corps established a small Aeronautics Division; Another bill called for the creation in the Signal Corps of an Aviation Section, instead of the existing Aeronautical Division ... this bill became law on July 18, 1914; On May 20, 1918, President Woodrow Wilson issued an executive order transferring aviation from the Signal Corps to two agencies under the Secretary of War: the Bureau of Aircraft Production ... and the Division of Military Aeronautics; On May 24, the War Department officially recognized the two Army agencies as comprising the Air Service) page 5 (The Air Corps Act of 1926 changed the name of the Air Service to Air Corps, but left unaltered its status as a combatant arm of the Army) page 7 (established the Army Air Forces on June 20, 1941) page 10 (The National Security Act of 1947 became law on July 26, 1947. It created the Department of the Air Force; Under the Department of the Air Force, the act established the United States Air Force)