Sixth Judicial Circuit (Illinois)
In 1835, during Abraham Lincoln's tenure in the Illinois House of Representatives, the General Assembly reorganized the state's existing five judicial circuits and created the Sixth Judicial Circuit, consisting of Cook, Henry, Iroquois, Jo Daviess, La Salle, Mercer, Peoria, Putnam, and Rock Island counties. In 1836, the legislature added the newly created counties of Kane, Ogle, Winnebago, and Will; and in 1837, Bureau County. In 1839, another shuffle of circuits defined Boone, Carroll, Jo Daviess, Rock Island, Stephenson, Whiteside and Winnebago counties as the Sixth Judicial Circuit; and in 1840, the legislature added the new county of Lee.
In 1841, the legislature again reorganized the state's judicial circuits, and this time defined the Sixth Judicial Circuit as consisting of Boone, Carroll, Henry, Jo Daviess, Lee, Mercer, Rock Island, Stephenson, Whiteside, and Winnebago counties.
An Act Dividing the State into Judicial Circuits; An Act to Establish Certain Counties; An Act to Establish the County of Will; An Act to Create the County of Bureau; An Act Dividing the State into Judicial Circuits; An Act to Attach the County of Lee to the Sixth Judicial District; An Act to Establish Circuit Courts.