An extremely rare original copy of the US constitution was sold Thursday for $43 million -- a world record for a historical document at auction, Sotheby's said.
It is one of only 11 known surviving copies of the US charter, signed on September 17, 1787 at Philadelphia's Independence Hall by America's founding fathers, including George Washington, Benjamin Franklin and James Madison and ratified the following year.
The winning bidder was not immediately identified.
A group of cryptocurrency investors had raised $40 million to buy the document but failed to secure the document, this consortium said.
A Sotheby's spokesman said the sale -- for $43.2 million including commissions -- was a world record for a historical document offered at auction.
Selby Kiffer, a manuscripts and ancient books expert at Sotheby's, said in September that this copy was probably part of an edition of 500 printed on the eve of the signing.
This one was the only one in private hands, Kiffer said.