After being traded to Philadelphia Athletics, in and , Anson finished in the NA's top five in batting, on-base percentage (OBP), and on-base plus slugging (OPS). He led the NA in OBP in 1872. His numbers declined slightly in 1874 and 1875, but he was still good enough that Chicago White Stockings secretary-turned-president William Hulbert sought him to improve his club for the season. Hulbert broke league rules by negotiating with Anson and several other stars while the season was still in progress and ultimately founded the new National League to forestall any disciplinary action.