The national anthem of the United States is "The Star Spangled Banner." The song was initially a poem written by Francis Scott Key in Sept. 1814, inspired by the defense of Fort McHenry.
"The Star Spangled Banner" was written by Key as he stayed overnight on a ship near Fort McHenry. Despite heavy artillery fire from the British, the American flag on the fort remained standing throughout the night, which is referenced within the song. "The Star Spangled Banner" was originally published as a poem called "Defense of Fort M'Henry," and achieved popularity after being attached to the tune of an obscure song called "To Anacreon in Heaven." The song was officially adopted as the national anthem of the United States in 1931.