World War II demonstrated how valuable air power was and the need to change the organization of the nation’s military forces. This resulted in the creation of a single Department of Defense with a strong Joint Chiefs of Staff with Army, Navy, and Air Force chiefs. The National Security Act, signed by President Truman on July 26, 1947, established this new defense organization and the United States Air Force as an independent service, equal to the Army and Navy. On September 18, 1947, Chief Justice Fred Vinson swore in Stuart Symington as the first Secretary of the Air Force, officially founding a new branch of the U.S. military on that day. For additional details about the Air Force’s founding and its birthday recognitions nationwide, courtesy of military.com, click here.