Star-Spangled Banner first edition sells for $500,000
An anonymous buyer has bid $506,500 for a first edition copy of the "Star-Spangled Banner" poem, whose words were adopted for the US national anthem.
It is the only first edition of the poem in private hands, and one of just 11 that exist, Christie's New York auction house said.
Francis Scott Key wrote a first draft of the poem in September 1814.
He was inspired after witnessing the defence of Baltimore's Fort McHenry against a British bombardment.
The poem was set to music and publisher Thomas Carr rushed the song to print. It was finally adopted as the US national anthem in 1931.
Christie's expert Chris Coover said that since the poem's publication it had "become in the intervening years an absolute true icon of American history and patriotism".
Mr Coover said of the work: "I'm fortunate enough to have been here 30 years. It's the first time I've ever handled one and it's quite a thrill."
The defence of the star-shaped Fort McHenry against the British navy occurred during the Battle of Baltimore on 13-14 September, 1814.
After 25 hours of continuous bombing, the British decided to leave since they were unable to destroy the fort as they had hoped.