The district covers parts of Cook, DuPage, Lake, Kane and McHenry counties.
Democrat Sean Casten is challenging Republican incumbent Peter Roskam.
Roskam is currently in his sixth term.
Before going to Washington, Peter Roskam served in both the Illinois House and Senate.
Democrat Sean Casten is a scientist and businessman with degrees in molecular biology and biochemistry.
He co-founded Recycled Energy Development which works to reduce greenhouse gas emissions.