Ernest Thompson Cox appeared in one game and pitched one inning for the 1922 Chicago White Sox, a team that shuttled 18 pitchers through their roster during the season. But thanks to his appearance in a big league uniform near a photographer, he made it into the E126 American Caramel set 5 years later. As far as we know, his pro career ended with that inning, Ernie having last played in the minors some years earlier.
http://www.baseball-reference.com/pl.../coxer01.shtml
Furthermore, thanks to his name similarity to Elmer Joseph "Dick" Cox, this E126 card appears on Beckett.com checklists as Dick Cox, despite Dick only ever playing for the Dodgers.
http://www.beckett.com/baseball/1927...ck-cox-3542695
Two obscurities, one card. I wrote a little more about it for the #5 blog.
http://www.number5typecollection.com...-5-et-cox.html