Rare first-edition copy of U.S. Constitution up for auction

An official first printing of the U.S. Constitution is set to go up for auction next month, New York-based auction house Sotheby's announced Tuesday. The historic document will be put up for auction during a dedicated live sale on Dec. 13.

It is one of only two such copies that are in private hands, and one of only 13 total copies known to exist, Sotheby's said. The other 11 are in public government collections. 

It's the first time in more than 125 years that this particular manuscript has gone up for auction, according to Sotheby's, which estimates it will sell for anywhere between $20 and $30 million.