 Standings at start of day | Results for August 18, 1888 Game 321: Kansas City 5, Chicago 4 |
| Game 321: Kansas City @ Chicago Kansas City 5, Chicago 4 Chicago Inter Ocean  | Game 322: Omaha @ Milwaukee Milwaukee 4, Omaha 1 Omaha Daily Bee  | Game 323: Des Moines @ Minneapolis Des Moines 5, Minneapolis 3 Minneapolis Star Tribune  | Game 324: Sioux City @ St. Paul Sioux City 8, St. Paul 7 St. Paul Globe  |