T205 Chase references Yankee fans...
http://www.ebay.com/itm/1911-T205-Go...YAAOSwJ4hY-2Fa
Also from WIKI:
Either "Yankees" or "Yanks" had been used frequently since 1904 in newspapers such as the New York Evening Journal, since "Highlanders" was hard to fit in headlines.[34] Such unofficial nicknames were common during that era,[15] but thereafter the official name took hold—the New York Yankees.[35]