Which of these organizations did the USAAF replace?

The United States Army Air Forces (USAAF) were created to provide the air arm a greater autonomy in which to expand more efficiently, to provide a structure for the additional command echelons required by a vastly increased force, and to end an increasingly divisive administrative battle within the Army over control of aviation doctrine and organization that had been ongoing since the creation of an aviation section within the Army Signal Corps in 1914. Accordingly the USAAF succeeded the USAAC in June 1941. It administered all parts of military aviation formerly distributed among the Air Corps, General Headquarters Air Force, and the ground forces' corps area commanders, and thus became the first air organization of the US Army to control its own installations and support personnel.