There were two Southern Illinois Leagues. The first operated in 1895as an independent league. In 1896 it was rated as an unclassified league. and the second League was 1910 as a Class D.
1895 Belleville IL, Cairo, IL, Duquion IL, East St Louis IL, Edwardsville IL, Murphysboro IL.
1896 Centralia IL, Duquion IL, Murphysboro IL, St Louis Mo
1910 Eldorado IL, Harrisburg IL, Herrin IL, McLeansboro IL, Mt Vernon IL