when was cook county established
Home D.O.C. Cook County was established on January 15, 1831 by the Illinois State Legislature. Chicago, then an unincorporated settlement with fewer than 60 residents, was designated the county seat.Due to a virtual absence of crime, a county courthouse and jail were not built until 1835.n 1969, the Illinois State Legislature finally acted. They voted into law a statute that created the Cook County Department of Corrections which combined the County Jail and the cityâs House of Corrections under one authority.