The National Security Act of 1947 ( not 1974 ) was a major reorganization of the Unites States governments military and intelligence agencies.
The Act merged the Department of War and the Department of the Navy into the National Military Establishment, headed by the Secretary of Defense. It created the Department of the Air Force and protected the Marine Corps as an independent service. The purpose of this act was to unify the Army, Navy and Air Force into a federal structure.
The Act also established the National Security Council for the coordination of issues of national security. Its goal was to advice the president on domestic and foreign security policies. The Act created the Central Intelligence Agency (CIA), the U.S. first peacetime intelligence agency.