 Standings at start of day | Results for June 12, 1888 Game 123: Chicago 12, Omaha 4 |
| Game 123: Omaha @ Chicago Chicago 12, Omaha 4 Chicago Tribune  | Game 124: Kansas City @ Milwaukee Milwaukee 7, Kansas City 3 Milwaukee Sentinel  | Game 125: St. Louis @ Minneapolis Minneapolis 11, St. Louis 8 Minneapolis Star Tribune  | Game 126: Des Moines @ St. Paul St. Paul 5, Des Moines 2 St. Paul Globe  |