In 1776, 500 copies of the Declaration of Independence were printed and only 23 copies were known to still exist before 1989. That same year, one man in Philadelphia bought an old painting at a flea market for $4 because he liked its frame. After it broke, the man discovered a document that appeared to be a copy of the Declaration of Independence tucked away between the canvas and its backing. Later on, the document was sold for $2.42 million at an auction.