George Washington's personal copy of the U.S. Constitution and Bill of Rights sold for $9.8 million at auction on Friday, setting a record for any American book or historic document.

Bidders at Christie's New York salesroom and others on the telephone competed for the first U.S. president's signed, gold-embossed volume dating to 1789, which had a pre-sale estimate of up to $3 million.

The non-profit Mount Vernon Ladies Association of the Union, which maintains the historic Mount Vernon estate in Virginia that was Washington's home and is now open to the public, was the successful bidder.

"The unique book has been in the Mount Vernon library until 1876, and will soon be returned to that library," said Chris Coover, senior specialist of books and manuscripts at Christie's.

The bound volume was Washington's personal copy of the Acts of Congress and is noteworthy for his bold signature marking it as his own.