GHQ Air Force was replaced by the Air Force Combat Command, and its four geographical districts were converted in January 1941 into numbered air forces, with a subordinate organization of 54 groups. Organizationally, the Army Air Forces was created as a higher command echelon encompassing both Air Force Combat Command and the Army Air Corps, thus bringing all of the air arm under a centralized command for the first time. Yet these reforms were only temporary, lasting just nine months as the air arm streamlined in preparation for war, with a goal of centralized planning and decentralized execution of operations.

Executive Order 9082 changed Arnold's title to "Commanding General, Army Air Forces" on March 9, 1942, making him co-equal with the commanding generals of the new Army Ground Forces and Services of Supply, the other two parts of the Army of the United States. War Department Circular No. 59 reorganized the Army Air Forces, disbanding the Combat Command (formerly GHQAF) and changing the Air Corps to a non-organizational combat arm, eliminating their layer of command. Replacing them were eleven numbered air forces (later raised to sixteen) and six major commands (which became eight in January 1943: Flying Training, Technical Training, Troop Carrier, Air Transport, Materiel, Air Service, Proving Ground, and Anti-Submarine Commands). In July 1943 Flying Training and Technical Training Commands merged into a single Training Command.

As a result of its exponential growth during World War II, the Army Air Forces became the world's largest and most powerful air force. The expansion from the Air Corps of 1939, with 20,000 men and 2,320 planes (a limit set in 1934), to the autonomous AAF of 1944, with almost 2.4 million personnel and 80,000 aircraft, was a remarkable feat. Robert A. Lovett, the Assistant Secretary of War for Air, together with Arnold, presided over an increase of personnel and equipment greater than for either the ground Army or the Navy, while at the same time dispatching combat air forces to theaters of war all over the globe.

The RWP Air Force collection consists of 138 pictures (10 pages) for $3.00, (listing only).