Recently the owner showed it to a friend "who became quite enthusiastic and urged him to look into it further," said Selby Kiffer, an Americana printing specialist at Sotheby's "At that point he called us."

"The discovery of any first-printing copy of the declaration, even a fragmentary one or a poor copy, would be exciting," Mr. Kiffer said. "But on this one, the condition is beyond reproach. It was folded up when we first saw it -- the way the owner said it was in the painting, less than one-tenth of an inch thick. I had to agree with him it was just as well that he kept it that way.

"There has been absolutely no restoration, no repair. It was unframed and unbacked." Only 7 of the 24 copies are unbacked, he said, which increases their value.

Mr. Kiffer said the declaration was the fourth copy of the first printing to surface in the last 10 years -- three of which were either known copies or had been handed down to heirs of the original 18th-century owners. The record for a declaration sold at auction is $1.6 million, which was realized in January 1990 in a Sotheby's sale of a copy from the estate of H. Bradley Martin, an heir to the Phipps steel fortune.

"The ink was still wet on this copy when it was folded," Mr. Kiffer said. "The very first line -- 'In Congress, July 4, 1776' -- shows up in the bottom margin in reverse, as a faint offsetting or shadow printing, one more proof of the urgency John Dunlap, the printer, and others felt in dispersing this document."