St. Elizabeths Hospital opened in 1855 as the first federally operated psychiatric hospital in the United States. Housing over 8,000 patients at its peak in the 1950s, the hospital at one point had a fully functioning medical-surgical unit, a school of nursing, and accredited internships and psychiatric residencies. Its campus was designated a National Historic Landmark in 1990.St. Elizabeths is in southeast Washington, D.C.. Since 2010, hospital functions have been limited to a portion of the east campus operated by the District of Columbia Department of Mental Health. The remainder of the east campus is slated for redevelopment by the District of Columbia which owns the site. The west campus is owned by the federal government and is being redeveloped for use as headquarters for the U.S. Department of Homeland Security and its child agencies.