𝗗𝗲𝗽𝗮𝗿𝘁𝗺𝗲𝗻𝘁 𝗼𝗳 𝘁𝗵𝗲 𝗡𝗮𝘃𝘆 "𝘼𝙡𝙬𝙖𝙮𝙨 𝘾𝙤𝙪𝙧𝙖𝙜𝙚𝙤𝙪𝙨" "𝘼𝙡𝙬𝙖𝙮𝙨 𝙁𝙖𝙞𝙩𝙝𝙛𝙪𝙡" The Department of the Navy comprises of the United States Navy and the United States Marine Corps. The Department of the Navy is headed by the Secretary of the Navy, also known as the SECNAV in naval jargon, who has the authority to conduct all of the affairs of the Department. The United States Department of the Navy was established by an Act of Congress on 30 April 1798 to provide a government organizational structure to the United States Navy and the United States Marine Corps.