From the time that the US military purchased its first aircraft in 1909 up to 1947, the US Air Force did not exist as a separate and independent military service organization. It went through a series of designations: Aeronautical Section, Signal Corps (1909); Aviation Section, Signal Corps (1914); United States Army Air Service (1918); United States Army Air Corps (1926), United States Army Air Forces (1941).
WWII illustrated the value of airpower, and the need to change the basic organization of the US Military Forces. The result was the creation of a single Department of Defense with a strong Joint Chiefs of Staff with Army, Navy, and Air Force chiefs. In 1947 President Truman signed the National Security Act which established this new defense organization, and along with it the creation of the US Air Force as an independent service, equal to the US Army and US Navy. The official birthday of the US Air Force is 18 September 1947.
Through the years history has shown the wisdom and foresight of the creation of a separate Air Force. The US Air Force emerged quickly from its cradle and began to create its own history and heritage.
Many thanks to all the brave men and women of the United States Air Force!