Aeronautical Division of the Army Signal Corps (1 August 1907 – 18 July 1914)
  

Aviation Section of the Signal Corps (18 July 1914 – 20 May 1918)
    

Division of Military Aeronautics (20 May 1918 – 24 May 1918)
  

Air Service of the U.S. Army (24 May 1918 – 2 July 1926)
  

U.S. Army Air Corps (2 July 1926 – 20 June 1941)
  

U.S. Army Air Forces (20 June 1941 – 17 September 1947)
  

U.S. Air Force (18 September 1947 to Present)
  

U.S. Military Aircraft Roundel Insignia (click to enlarge)