It features a special primary for the 2nd Congressional District and 31 local contests.
Voting sites are open Saturday from 9 a.m. to 5 p.m.
According to the Cook County Clerk's Office, there are 10 early voting sites in suburban Cook County plus the clerk's downtown Chicago office at 69 W. Washington.
For a list of suburban sites: www.cookcountyclerk.com/elections/earlyvoting/Pages/EarlyVotingLocations.aspx