Fort McHenry, in Baltimore, Maryland, is a historical American coastal star-shaped fort best known for its role in the War of 1812, when it successfully defended Baltimore Harbor from an attack by the British navy in Chesapeake Bay September 13–14, 1814. It was first built in 1798 and was used continuously by U.S. armed forces through World War I and by the Coast Guard in World War II. It was designated a national park in 1925.