As atmospheric flight became more advanced, a new service of the Army was created in 1941, the US Army Air Force (USAAF), into which the former Air Corps was integrated, and formed a subordinate organization.
In September 1947, a separate branch of the Army Forces, the US Air Force was created. It assumed all the missions of the former USAAF, except for some parts of the Air Corps (light aircraft aiming at supporting ground operations) which remained in the Army under that name.
In July 1947, three Ferengi crashed near Roswell, New Mexico, close to an USAAF air base (Roswell Army Airfield). Specialists from the research facility of the Air Corps Wright Base (Ohio) came to investigate. (DS9: "Little Green Men")