While pitching for the
Birmingham Barons in 1902, Wilhelm threw back-to-back one-hit games. This attracted the attention of
Pittsburgh Pirates owner
Barney Dreyfuss, who invited Wilhelm to spring training with the Pirates in 1903. Wilhelm appeared in 12 games that year for the Pirates, finishing with a 5–3
win–loss record. He played with the
Boston Beaneaters in the next two seasons. In 1904, Wilhelm earned a 14–20 record and gave up a league-high 118
earned runs. The next year he gave up 122 earned runs, second highest in the league, and finished with a 3–23 record. Wilhelm became commonly known as "Kaiser" during his career, a nickname which originated from the early 20th century German emperor
Wilhelm II. . Playing with the Barons in 1906, Wilhelm pitched the team's first
perfect game since its founding in 1884. The 1906 Barons won the team's first title since joining the
Southern Association in 1901. His record that year was 22–13. He had similar success the following year, finishing 23–14. In his three seasons with Brooklyn, he registered a 22–42 record. Before the 1914 baseball season, Wilhelm was signed by the
Baltimore Terrapins of the
Federal League (FL). In 1915, the new
Colonial League emerged with backing from the FL. An agreement between the leagues provided each Colonial League team with six FL players; the FL received $200 per month for each player sent to the new league. When ordered to the new league by FL officials, Wilhelm refused to report. Instead, he was made an FL umpire. In 1916, Wilhelm sued the Terrapins on the grounds he had signed a three-year contract in 1914 worth $10,500 and was not allowed to continue with the team after July 1, 1915. Wilhelm spent the 1916 and 1917 seasons with the
Elmira Colonels of the
New York State League. In those two seasons, he finished 14–19 and 17–16 respectively. Wilhelm became manager of the
Philadelphia Phillies during the 1921 season. In early September,
The New York Times criticized Wilhelm's team after losing both games of a doubleheader, saying that "Every day is Labor Day for the Phillies... The Quakers were in perfect stride during both contests and demonstrated they can lose as easily and dexterously on a holiday as on any other occasion." Wilhelm had become the interim manager earlier in the season after
Wild Bill Donovan was called as a witness in the trial surrounding the
Black Sox Scandal. Wilhelm was discharged from his position in late 1922. Wilhelm's managerial record was 83–137 in Philadelphia, which included 96 losses in 1922. In 1923, Wilhelm made his final professional appearance as a player, taking part in a single game with the
Rochester Tribe. He then managed the
Bridgeport Bears in 1925. Wilhelm died in 1936 and a benefit minor league game was held in Rochester to assist his widow. ==Scoreless innings streak==