I found this February 3, 1908 letter that Dickey Pearce wrote to Sam Crane at the Robert Edwards Auction website. It sold for $5287.50 in 2007. Crane was investigating the origins of the curveball and Pearce offered a few thoughts. In the letter, he wrote the following:
Friend Crane - I see by the journal that was sent me from New York I see that you want hear from the old players. I think I am the oldest player. You want the name of the first curved a B Ball not one in front of a bar. I have seen a grate [sic] many but Boby [sic] Mathews was the first that I ever saw when he came to New York with a club from Loway and dumped all that went against him but if you will consult pop Chadwick or Will N. Rankin of the New York Clipper you may get what you are looking for as they have all the records from way back when the ball took its first curve. - Hope that you will meet with success. I remain yours truly - Dicky Pearce.