“The Star-Spangled Banner” became the official U.S. national anthem in 1931.
Congress passed a joint resolution on March 3, 1931, and President Herbert Hoover signed it the following day. The law ended decades in which the United States had patriotic songs but no officially designated national anthem.
The song’s words came from Francis Scott Key’s 1814 poem about the Battle of Baltimore. Its melody was adapted from “The Anacreontic Song,” written by English composer John Stafford Smith for a London gentlemen’s club.
The anthem officially contains all four stanzas of Key’s poem, although public performances almost always use only the first. Before 1931, “Hail, Columbia” and “My Country, ’Tis of Thee” often served as de facto patriotic anthems at official events.