His beloved Chicago Cardinals finally won the NFL championship eight months after his death. But six years before he purchased the club, Charles Bidwill owned a racing stable, served as president of the Chicago Stadium Operating Company and ran a printing company - Bentley, Murray & Co., where he signed this letter "C.W. Bidwell" (9/10 out of 10 overall), which referenced the development of the horse racing photo-finish camera and he had sample pictures attached. Typed on multi-colored company letterhead, the content includes the Derby Day ticket the company printed at the top center. The letter has a couple of rust spots from paper clips, but this is easily one of the three toughest Football Hall of Fame autographs to obtain with fewer than 10 examples known to exist, making it one of the true Holy Grail signatures!