Tourists explore <PERSON>'s home in Springfield, Ill. It's been more than 25 years since workers renovating <PERSON>'s home found a letter fragment in a mouse's nest inside a wall. But researchers with The Papers of Abraham Lincoln think they've finally identified the author of the mystery letter as newspaper editor <PERSON>. The March 10, 1846, letter sent from Quincy, Ill., was <PERSON>'s reply to a poem the future president had shared with him.