Baseball steadily became popular as Marshalltown grew in the mid-1800s. Adrian's brother Sturgis also became a talented baseball player and both went to play on intra-school teams at the University of Notre Dame. Both later returned to Marshalltown to play baseball for the town team. Along with their father Henry, the town's founder, they put together a team and became the most prominent team in the state of Iowa. The Marshalltown team, with Henry Anson at third base, Adrian's brother Sturgis in center field, and Adrian at second base, won the Iowa state championship in 1868. In 1870 Marshalltown played an exhibition game with the talented Rockford Forest Citys. Although Marshalltown lost the game, Rockford's management offered contracts to all three of the Ansons. Adrian accepted the contract, which began his professional career in baseball in 1871.