Celebrating 73 years of US Air Force legacy Published Sept. 18, 2020 By Public Affairs 624th Regional Support Group JOINT BASE PEARL HARBOR-HICKAM, Hawaii -- The National Security Act of 1947 was implemented Sept.18 giving birth to a brand new military branch of service, the United States Air Force. President Harry Truman signed the National Security Act of 1947 on July 26, 1947, and this act officially set in motion the establishment of the U.S. Air Force as a separate and co-equal branch of the U.S. Armed Forces. According to the National Museum of the United States Air Force, the U.S. Air Force’s journey for independence was a long and contentious struggle between “air-minded officers” and those devoted to the Army and Navy mindset. The creation of an independent air arm, crucial to national defense, had been championed for decades by a succession of Army Air Corps and Army Air Forces senior leaders. American air dominance through the Army Air Corps in World War II started the path to a separate service. Careful post-war organizational planning by Gen. Henry Arnold demonstrated the effectiveness of air power and the need for an independent Air Force to political leaders. President Truman, by signing this act into law, validated the dedication and sacrifice of thousands of Airmen who worked to create the most powerful air force in the world. Stuart Symington was sworn in as the first Secretary of the Air Force by Chief Justice Fred Vinson on Sept. 18, 1947, which established the U.S. Air Force as truly an independent arm of the U.S. military.