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.