Francis Scott Key wrote "The Star-Spangled Banner" in 1814 after witnessing the large American flag still waving over Fort McHenry in Baltimore following a night of British naval bombardment during the War of 1812. Inspired by the flag, Key penned the poem that would later become the lyrics of the national anthem. Congress officially designated "The Star-Spangled Banner" as the national anthem in 1931, over 100 years after it was first performed.