United States Army Air Force
The Air Corps became the Army Air Forces in June 1941 to provide the air arm a greater autonomy in which to expand more efficiently, and to provide a structure for the additional command echelons required by a vastly increased force. Although other nations already had separate air forces independent of the army or navy (such as the British Royal Air Force and the German Luftwaffe), the USAAF remained a part of the United States Army.