Gagney played Geo. M Cohan in the movie "Yankee Doodle Dandy". Cohan was friends with Tod Sloan. Cohan, in 1904, produced and starred in a musical based on Tod Sloan called "Little Johnny Jones". Since everyone has seen the movie, the rest is, as they say, history.
BTW, I believe that Sloan's named is mispelled on the chip --- even more valuable!!