The National League and American Association's regular seasons ended on October 15, with the Providence Grays and New York Metropolitans as the NL and AA pennant winners, respectively.
The newly-founded Union Association regular season ended on October 19, with the St. Louis Maroons as the UA pennant winner.
The Union Association was largely unstable throughout its only year in existence (though confidence in the league remained high), as three of its founding teams would not make it to the end of the season.
The Philadelphia Keystones folded on August 7, and were replaced by the Eastern League's Wilmington Quicksteps.
Union Association Opening Day took place on April 17 featuring six teams, while American Association and National League Opening Days took place on May 1, featuring all twelve and all eight teams, respectively.