Today, September 18, 1947,  the US Air Force was “born” with the implementation of the National Security Act of 1947. This was a major restructure of the nation’s military after World War 2. It created the National Military Establishment (later remodeled as the Department of Defense), the Department of the Air Force as a sub-department, the Central Intelligence Agency, and the National Security Council. The Army Air Forces became the United States Air Force.