It was created under "The National Security Act of 1947" At that point it separated from the Army AirCore and became the US Air Force.
The US Air Force did not exist in either WWI or WWII. The US Air Force was created in 1947 and fought its FIRST war in Korea in 1950.
In WWII the US Army Air Force and the US Naval Air Forces fought the war. In 1947 President Truman created the US Air Force. The Korean War was the FIRST war fought by the United States Air Force.
The US Air Force was created from the US Army Air Corps, and the Army ranks were retained, so 2nd lieutenant is the lowest. The term 3rd lieutenant is used, but it applies to Air Force cadets (not officers yet) training on US Air Force bases.
US Air Force Ordnance dept.
Army Air Force as the US Air Force as it's own entity hasn't been created yet.
Twelfth Air Force was created in 1942.
Bangladesh Air Force was created in 1971.
Venezuelan Air Force was created in 1946.
Senegalese Air Force was created in 1961.
Air Battle Force was created in 2003.
Cameroon Air Force was created in 1960.
Syrian Air Force was created in 1948.