In 1884 Sweeney won 41 games, helping pitch two major league clubs to pennants. After winning 17 for Providence (NL), he was expelled from the league for leaving the field in the middle of a game, and promptly signed with St. Louis in the rival Union Association, where he won 24. With Providence on June 7, he struck out 19 Boston batters to set a ML record for a nine-inning game that, though tied four times, was not broken until Roger Clemens struck out 20 in 1986. In 1894 Sweeney killed a man in a San Francisco saloon. Sentenced to prison, he died there eight years later.