Collection of all 56 signers of Declaration on sale

A rare collection of Revolutionary war autographs is making a stop in Philadelphia before going on the auction block.

The complete set of all 56 men who signed the Declaration of Independence is expected to fetch more than $1 million at auction next month. Today, the collection is being displayed at the site of the future Museum of the American Revolution in the city's historic district.

New Hampshire-based auction house RR Auction calls it the ultimate accomplishment in American autograph collecting. The auction house said most of the signatures are part of letters by some of the nation's most important Founding Fathers.

The auctioneer said a highlight is the autograph of Georgia signer Button Gwinnett. Only 51 examples of his handwriting are known to exist.