"The Star-Spangled Banner" is the national anthem of the United States. The lyrics come from the "Defence of Fort M'Henry", a poem written by American lawyer Francis Scott Key on September 14, 1814, after he witnessed the bombardment of Fort McHenry by the British Royal Navy during the Battle of Baltimore in the War of 1812. Key was inspired by the large U.S. flag, with 15 stars and 15 stripes, known as the Star-Spangled Banner, flying triumphantly above the fort after the battle.

A national anthem is a patriotic musical composition symbolizing and evoking eulogies of the history and traditions of a country or nation. The majority of national anthems are marches or hymns in style. American, Central Asian, and European nations tend towards more ornate and operatic pieces, while those in the Middle East, Oceania, Africa, and the Caribbean use a more simplistic fanfare. Some countries that are devolved into multiple constituent states have their own official musical compositions for them ; their constituencies' songs are sometimes referred to as national anthems even though they are not sovereign states.