Though a celebrated part of American culture today, "The Star Spangled Banner" has not always been America's national anthem. In fact, some people might argue that the song wasn't always American. How did Francis Scott Key's poetic tribute to the defense of Fort McHenry during the War of 1812 come to be one of the most revered and recognizable songs in America, gaining legal status as the official song of the United States?

When Key, a slaveholder, lawyer, and sometime poet, penned the "Star Spangled Banner," he wanted to give words to his emotions after witnessing the 1814 defense of Baltimore from British invasion. Just after dawn, Key looked to see whether the British or the Americans had taken the day. What he saw stirred him—a huge American flag, the "star-spangled banner," still flying at the fort. On the back of a letter Key immediately began composing...