The National League and the American Association faced each other in a World's Championship Series at the end of the season to determine an overall champion.
Champ
NYG
1888 AA Champion New York Giants
z: best record, c: conference winner, y: division winner, w: wildcard, x: clinched playoff spot

World's Championship Series

Best of 11-game series
Date    OpponentResultScoreSeries
10/16at NY GiantsL  1-2 0-1
10/17at NY GiantsW  3-0 1-1
10/18at NY GiantsL  2-4 1-2
10/19vs NY GiantsL  3-6 1-3
10/20at NY GiantsL  4-6
8
1-4
10/22vs NY GiantsL  5-12
8
1-5
10/24vs NY GiantsW  7-5
8
2-5
10/25vs NY GiantsL  3-11 2-6
10/26vs NY GiantsW  14-11
10
3-6
10/27vs NY GiantsW  18-7 4-6