The charter franchises were in the Illinois cities of Belleville, Centralia, Marion, Mattoon, Mount Vernon and West Frankfort.
The Illinois State League had the same six franchises in both of its seasons: the Belleville Stags, Centralia Cubs, Marion Indians, Mattoon Indians, Mount Vernon Braves, and West Frankfort Cardinals.
There was no championship series in 1947 as the Belleville Stags won both halves and were declared as the champion.
The name change occurred as the Marion Indians moved to the state of Kentucky to become the Paducah Chiefs.
[6] The 1948 Illinois State League All–Star Game was July 12, 1948 at Mattoon Baseball Park.