The Star-Spangled Banner, or the Great Garrison Flag, was the garrison flag that flew over Fort McHenry in Baltimore Harbor during the naval portion of the Battle of Baltimore during the War of 1812. It is on exhibit at the National Museum of American History, Smithsonian Institution. Seeing the flag flying over Fort McHenry on the morning of September 14, 1814, after the battle ended, Francis Scott Key was inspired to write the poem "Defence of Fort M'Henry". These words were written by Key and set to the tune of "To Anacreon in Heaven", a popular song at the time, by John Stafford Smith. In 1931 the song became the national anthem of the United States.

Fort McHenry is a historical American coastal pentagonal bastion fort on Locust Point, now a neighborhood of Baltimore, Maryland. It is best known for its role in the War of 1812, when it successfully defended Baltimore Harbor from an attack by the British navy from Chesapeake Bay on September 13–14, 1814.