The below information is by no means complete. It is the basic historical information that you will study (and be tested on) in basic training.
Before 1947, the Air Force was part of the United States Army. The National Security Act of 1947 changed this. Among other things, the act created a separate and independent United States Air Force.
The National Security Act of 1947
On 17 September 1947, a long-held dream of American military aviators became factthe United States Air Force came into being as a separate organization. The creation of the air force came after protracted wrangling and negotiations in Washington DC, primarily between the embryonic air wing and the US Navy. Despite the host of conferences, studies, and political fights, the National Security Act of 1947 gave formal recognition of what had been virtually an independent air wing since early in WWII.
The new US Air Force in theory was a coequal part of the national military establishment. It had a Chief of Staff (General Carl Spaatz) and a Secretary of the Air Force (Stuart Symington) serving under the newly organized Department of Defense. The old US Army Air Force and Army Air Corps ceased to exist and were absorbed into the new organization.
For the average enlisted airman, the immediate change was scarcely noticeable. In many areas, the establishment of the Air Force had little impact on the lives of enlisted personnel until months or even years had passed. What were designated as organic service units were taken over as newly designated air force units. Units that provided a common service to both the Army and the Air Force were left intact. Until 1950, for example, if an enlisted airman became seriously ill, he was likely treated by Army doctors in an Army hospital.
There was also, at first, no change in appearance. The distinctive blue uniforms of the US Air Force were introduced only after large stocks of Army clothing were used up. Familiar terms slowly gave way to new labels. By 1959, enlisted airmen ate in dining halls rather than mess halls, were eyed warily by air police instead of military police, and bought necessities at the base exchange instead of the post exchange.
Initially, the rank system remained as it had been in the USAAF. Corporal was removed from NCO status in 1950. Then, in 1952, the Air Force officially changed the names of the lower four ranks from Private to Airman Basic; Private First Class to Airman, Third Class; Corporal to Airman, Second Class; and Sergeant to Airman, First Class. These changes were in response to a development that surfaced during WWII. The enlisted ranks of the Air Force were packed with highly skilled technicians who sought and received NCO ranks as a reflection of their training and value to the service. Eventually, a relative abundance of sergeants, many of whom did not play the traditional lower management role of sergeants in the Army, permeated the Air Force. The establishment of a separate Air Force and the multiplying sophistication of air force hardware put emphasis on specialists who were rated as staff sergeants or technical sergeants.
Promotion and specialization went hand in hand with training in the new Air Force. When the new organization established Air Force specialty codes (AFSC) as standard designations for functional and technical specialties, qualification for an advanced AFSC became part of the criteria for promotion. During the late 1940s, the Air Force also began an Airman Career Program that attempted to encourage long-term careers for enlisted specialists.