A rare first edition of the lyrics and music of the United States national anthem has been sold at auction to an anonymous bidder for $US506,000.
The two-page, 1814 lyrics of The Star Spangled Banner was described by Christie's auction house in New York as a true icon of American history and patriotism.
Christie's said it was the last of 11 copies in private hands.
Francis Scott Key wrote a first draft of the poem during the Battle of Baltimore on 13-14 September, 1814.
The BBC reports he was inspired after witnessing the defence of Fort McHenry against a bombardment by the British navy.
The poem was set to music and sold as a song by publisher Thomas Carr.
It was finally adopted as the US national anthem in 1931.