Categories: Congressional districts of Illinois | Cook County, Illinois | United States government stubs Image:Illinois2nd. ... Illinois 6th congressional district is a United States Congressional District that represents the western suburbs of Chicago, including portions of DuPage and Cook counties. ... Illinois 8th congressional district is a United States Congressional District that represents the northern suburbs of Chicago, including portions of Lake, McHenry, and Cook counties. ... This page has the current U.S. congressional delegation from the state of Illinois. ... These are tables of congressional delegations from Illinois to the United States Senate and United States House of Representatives. ... Congressional districts for representation in the United States House of Representatives are determined after each census. ... US Congressional apportionment for states in 2000 The membership of the United States House of Representatives changes each decade following the decennial United States Census. ... The process known as redistricting in the United States and redistribution in many Commonwealth countries is the changing of political borders (in many countries, specifically the electoral district/constituency boundaries) usually in response to periodic census results. ... Gerrymandering is a controversial form of redistricting in which electoral district or constituency boundaries are manipulated for an electoral advantage. ...