The Lansing Lugnuts and Wisconsin Timber Rattlers franchises jointly have won the most Midwest League championships, with nine each.

In 1949, the ISL changed its name to the Mississippi–Ohio Valley League after Marion moved their franchise to Kentucky and became the Paducah Chiefs.

The original teams in 1956, the first year of Midwest League play, were: Clinton Pirates, Decatur Commodores, Dubuque Packers, Kokomo Dodgers, Lafayette Red Sox, Mattoon Phillies, Michigan City White Caps and the Paris Lakers.

[4] The 1975 Waterloo Royals, led by future MLB All-Stars Willie Wilson and Dan Quisenberry, are ranked #60 on MiLB.com's Top 100 Teams.

In 1982, the league expanded from 8 to 12 teams, adding the Beloit Brewers, the Danville Suns, the Madison Muskies, and the Springfield Cardinals.

In 1988, the league began splitting its season into two halves and expanded from 12 to 14 teams, with the addition of franchises in South Bend, Indiana, and Rockford, Illinois.

Harry Chappas, Ross Baumgarten and Britt Burns were all called up to the parent Chicago White Sox at the conclusion of the MWL season.