The United States Naval Academy is a four-year coeducational federal service academy in Annapolis, Maryland. Secretary of the Navy George Bancroft began it in 1845. It is the second-oldest of the United States' five service academies. It educates officers mostly to join the United States Navy and Marine Corps. The 338-acre (137 ha) campus is on the former grounds of Fort Severn where the Severn River flows into Chesapeake Bay. It is about 33 miles (53 km) east of Washington, D.C. and 26 miles (42 km) southeast of Baltimore, Maryland. The entire campus is a National Historic Landmark. The campus has many historic sites, buildings, and monuments. One monument is the Herndon Monument, once a year the upper three classes add grease and challenge the freshmen to reach the tip.