The original letter signed by President Abraham Lincoln three days before his 1865 assassination. Photo courtesy of the Raab Collection/UPI Feb. 19 (UPI) -- A rare document signed by President Abraham Lincoln at the White House three days before he was killed was found in a desk and is now up for auction. "This is a rare opportunity to own something signed by Lincoln in his last days, and in fact on the day of his last speech to the public," says the Raab Collection, which has valued the signed Lincoln document at an estimated $45,000. Advertisement According to Raab,...