Iowa State League was a Class D League from 1905-1906. in 1907 the league change is name to Central Association, a Class D League and before the Iowa State League started, it was called Iowa State Association,1904, a Class D League.
Iowa State league was an Independent League that played in 1895, 1911-1912 and 1950-1955.
1895 Burlington IA, Cedar Rapids IA, Dubuque Ia, Ottumwa IA
1904 Boone IA, Burlington IA, Ft Dodge IA, Keokuk IA, Marshalltown IA, Oskaloosa IA, Ottumwa IA, and Waterloo IA.
1905 No teams entered the league or left the league.
1906 Boone, IA move to Clinton, IA during the season.
1907 Jacksonville, IL and Quincy, IL entered the league; Clinton and Ft Dodge left the league.
1912 Clear Lake IA, Emmetsburg IA, Estherville IA, Ft Dodge IA, and Mason City IA.
A new semi-pro Iowa State League formed in 1949. The semi-pro ISL lasted until 1955.
1949 Bancroft, Carroll, Lakes (Wall Lake and Lake View combined entry), Marshalltown, Mason City, Spencer
1950 Marshalltown dropped from the League. Audubon, Estherville, Fonda, Schaller and Storm Lake join the ISL with the League split into north and south divisions.
1951 Audubon, Fonda and Schaller left the league and Denison joined the Wall Lake / Lake View partnership to form the Lakes - Denison with home games split roughly between Denison, Wall Lake and Lake View.
1952 Wall Lake entered an all-black team in the League when both Denison and Lake View dropped from the Lakes - Denison partnership. Bancroft also left the league. The Wall Lake Popcorn Kernels failed early in the season resulting in only teams finishing the season.
1953 Storm Lake and Bancroft entered the league.
1954 Bancroft dropped from the League.
1955 Bancroft entered the league.
NOTE 1 - Bold Means unknown Location.
NOTE 2 - Unsure but i think the teams that played in 1895 were also played in the Eastern Iowa League