Salute to Services
The mission of the United States Navy is to maintain, train and equip combat-ready naval forces capable of winning wars, deterring aggression and maintaining freedom of the seas.
The U.S. Navy was founded in 1775, and the Department of the Navy was established in April 1798. The Department of the Navy has three principal components: the Navy Department consisting of executive offices, mostly in Washington, DC; the operating forces, including the Marine Corps, the reserve components and, in time of war, the U.S. Coast Guard (in peace, a component of the Department of Homeland Security); and the shore establishment.
— from the website www.navy.mil.