The first lines of the first stanza of the national anthem pose the question about whether the American flag is still visible flying above Fort McHenry in Chesapeake Bay. Author Francis Scott Key witnessed the War of 1812 naval Battle of Fort McHenry from a British ship where he was temporarily being held prisoner. He was unable to determine who was winning the battle, but he realized that as long as the American flag was flying above the fort, there had been no American surrender. In the sixth line, the "proof" that is being shown is the visibility of the American flag above the fort. Key could not have seen the flag in the total darkness, but the "rockets' red glare" and "the bombs bursting in air" lit up the sky enough for Key to see that the flag was "still there."