League franchises were based in Indiana, Kentucky, Michigan, Ohio and West Virginia.
The first 20th century Ohio State League started in 1908 as a class D loop and ran through 1916.
Another Ohio State League was formed in 1936 and ran through 1947 except for a break in '42-'43 due to World War II.
In 1945, the OSL was one of just four class D circuits in operation, yet it was one of the first of dozens of leagues to collapse after World War II.
The Portsmouth Cobblers won four Ohio State League championships.
Baseball Hall of Fame member Ed Delahanty played for the 1887 Mansfield team.
1909 Ohio State League Newark and Lancaster both disbanded August 23.