1887 Major League Baseball season

1887 MLB season
LeagueAmerican Association (AA)
National League (NL)
SportBaseball
DurationRegular season:
  • April 16 – October 10, 1887 (AA)
  • April 28 – October 8, 1887 (NL)
World's Championship Series:
  • October 10–26, 1887
Number of games140 (AA)
126 (NL)
Number of teams16 (8 per league)
Pennant winner
AA championsSt. Louis Browns
  AA runners-upCincinnati Red Stockings
NL championsDetroit Wolverines
  NL runners-upPhiladelphia Quakers
World's Championship Series
ChampionsDetroit Wolverines
  Runners-upSt. Louis Browns
Locations of teams for the 1887 American Association season
American Association

The 1887 major league baseball season began on April 16, 1887. The regular season ended on October 10, with the Detroit Wolverines and the St. Louis Browns as regular season champions of the National League and American Association, respectively. The postseason began with Game 1 of the fourth World's Championship Series on October 10 and ended with Game 15 on October 26, in what was a best-of-fifteen-playoff, played across 10 cities. The Wolverines defeated the Browns, ten games to five (and clinching on Game 11), capturing their first World's Championship Series.

The Louisville Colonels set a Major League record which still stands for the most base on balls for a team in a game, with 19 against the Cleveland Blues on 21 September.

Over the offseason, the National League's Kansas City Cowboys folded, and saw them replaced by the American Association's Pittsburgh Alleghenys. In place of the Alleghenys leaving the AA for the NL, the Cleveland Blues were enfranchised. Meanwhile, the St. Louis Maroons relocated to Indianapolis, Indiana as the Indianapolis Hoosiers.