United States Department of the Navy
The United States Department of the Navy (DON) is one of the three military departments within the United States Department of Defense. It was established by an Act of Congress on 30 April 1798, at the urging of Secretary of War James McHenry, to provide a government organizational structure to the United States Navy (USN).
Source: Wikipedia — United States Department of the Navy (CC BY-SA 4.0)