The 1899 was the final season of a stable 12-team, eight-season run which saw no expansion or contraction of teams.
Following the end of the season, the National League contracted from 12 to 8 teams, eliminating the Baltimore Orioles, Cleveland Spiders, Louisville Colonels, and Washington Senators.
The 1899 season is famous for the Cleveland Spiders finishing with the worst single-season record of all time (minimum 120 games), finishing at a dismal 20–134 (.130), largely due to the fact that the Spiders-owning Robison family bought the St. Louis Perfectos prior to the 1899 season, then proceeded to move all Cleveland talent to St. Louis, leaving the Spiders a talent-depleted team.
The only other major-league team of the 19th century with a worse record was the 1884 Wilmington Quicksteps, who entered the unstable single-season Union Association as a late-season replacement for the Philadelphia Keystones and played only 18 games, with a record of 2–16 (.111).
The 1899 schedule consisted of 154 games for the twelve teams of the National League.