About

The United States Department of the Navy (DN) is one of the three military departments within the Department of Defense of the United States of America. The Department of the Navy was established by an Act of Congress on 30 April 1798 (initiated by the recommendation of James McHenry), to provide a government organizational structure to the United States Navy (USN), the United States Marine Corps (USMC) (from 1834 onward) and, when directed by the President (or Congress during time of war), the United States Coast Guard (USCG), as a service within the Department of the Navy, though each remain independent service branches.

The Department of the Navy was an Executive Department and the Secretary of the Navy was a member of the President's cabinet until 1949, when amendments to the National Security Act of 1947 changed the name of the National Military Establishment to the Department of Defense and made it an Executive Department. The Department of the Navy then became, along with the Department of the Army and Department of the Air Force, a Military Department within the Department of Defense: subject to the authority, direction and control of the Secretary of Defense.