Similar in educational and training nature to the U.S. Military Academy, the naval academy at Annapolis, MD, trains and educates men and women for service in the U.S. Navy and U.S. Marines. Graduates are commissioned either as second lieutenants in the Marine Corps or as ensigns in the Navy. The academy itself is a U.S. National Historic Site. It was founded in 1845 at Fort Severn. Originally the course of study sandwiched three years of sea duty around two years of academic training. Since an 1851 reorganization, the course of study has been a four-year curriculum, with two summer cruises. Unlike the U.S. Military and Air Force Academy, the U.S. Naval Academy has both a tenured civilian and military faculty.