The Wisconsin State League was a class D level baseball league that began in 1905, changing its name to the Wisconsin–Illinois League in 1908 and operating through 1914. The league re–organized under that name in 1926. Another Wisconsin State League began in 1940, shut down during World War II from 1943 through 1945, then operated from 1946 through 1953.

The Class D Wisconsin–Illinois League began play in 1940 with six charter franchises: Appleton Papermakers, Fond du Lac Panthers, Green Bay Bluejays, La Crosse Blackhawks, Sheboygan Indians and Wisconsin Rapids White Sox. In 1942 the league expanded to eight teams, adding the Janesville Cubs and Oshkosh Giants. After play resumed in 1946, La Crosse moved to become the Wausau Lumberjacks and the league operated with those franchises until its demise following the 1953 season.

Wisconsin State League (1905–1907, 1922–1925, 1928–1931, 1940–1942, 1946–1953)
Wisconsin–Illinois League (1908–1914, 1926–1927, 1932)

1891 Wisconsin State League

1905 Wisconsin State League

1906 Wisconsin State League
schedule

La Crosse played Freeport on the last day of the season with the pennant in balance. 5,000 fans saw a 0–0 game after nine innings. La Crosse pushed across five runs in the tenth to win.

1907 Wisconsin State League
schedule