Question: When was the fort commanded by George Armistead during the Battle of Baltimore first built?

Related documents: [0]  [DOC] Fort McHenry, in Baltimore, Maryland, is a historical American coastal pentagonal bastion fort best known for its role in the War of 1812, when it successfully defended Baltimore Harbor from an attack by the British navy from the 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, and in 1939 was redesignated a "National Monument and Historic Shrine". [END] 
[1]  [DOC] George Armistead (April 10, 1780 – April 25, 1818) was an American military officer who served as the commander of Fort McHenry during the Battle of Baltimore in the War of 1812. [END]  
Answer: 1798
1798