In 1899, Wallace moved to the St. Louis Perfectos (renamed the Cardinals in 1900) and changed position again, this time to shortstop. He once again had a solid offensive season, hitting .295 with 108 RBI and 12 home runs (second in the league). Wallace jumped teams again in 1902, when he joined the St. Louis Browns. His playing time began deteriorating a decade later and he didn't play more than 55 games in any season after 1913. He moved back to the Cardinals in 1917 and retired after the 1918 season. He retired with a .268 batting average, 1059 runs, 34 home runs, 1121 RBI and 201 stolen bases.
Wallace managed and umpired when his playing time diminished. He managed the 1911 and 1912 Cardinals and part of the 1937Cincinnati Reds season, compiling 62 wins and 154 losses for a .287 winning percentage. Upon retiring, he also became a scout.