In 1989, a Philadelphia financial analyst visited a flea market in Adamstown, Pa., spotted an old painting whose frame he liked, and purchased it for $4.

When he removed the frame, he found a folded document between the picture canvas and the wood backing. And the document appeared to be the Declaration of Independence.

It was. He had discovered an original printing of the Declaration from its first printing in 1776. Sotheby’s auctioned it for $2.42 million in 1991, then again for $8.14 million in 2000.

“This was how Congress voted to disseminate the news of independence,” said Sotheby’s vice chairman David Redden. “So it was printed up from Thomas Jefferson’s draft of the Declaration and then sent around by couriers to the armies in the field, to the newly independent colonies, to the committees of public safety, and surely to the British, too.”

How it got into the painting is unknown.