Cook County, Illinois

County: Cook

State: Illinois

Lat/Long: 41.8333, -87.8500

On January 15, 1831, the Illinois General Assembly formed Cook County from Putnam County. Legislators named the county for Daniel P. Cook, the first attorney general of Illinois and member of the U.S. House of Representatives (1819-27) who secured the first federal grant of land to facilitate the construction of the Illinois and Michigan Canal. The enabling act established Chicago as the permanent county seat. In March 1831, voters elected the first county officials, and in September the county and circuit courts took up residence at Fort Dearborn. In 1835, the county constructed a permanent courthouse on the corner of Clark and Randolph streets. Between 1831 and 1839, the General Assembly reduced the county's borders by carving out the new counties of McHenry, Will, Dupage, and Lake, thereby setting the boundaries of Cook at their current limits.

"An Act to Create and Organize the Counties Therein Named," 15 January 1831, Laws of Illinois (1831), 54-57; Origin and Evolution of Illinois Counties (Springfield: Illinois Secretary of State, 2010), 9-11, 60; A. T. Andreas, History of Cook County Illinois (Chicago: A. T. Andreas, 1884), 116; Weston A. Goodspeed and Daniel D. Healy, eds., History of Cook County Illinois, 2 vols., (Chicago: Goodspeed Historical Association, 1909), 2:217-18; An Act for the Relief of Cook County.