Today is the last day for residents of 15 states to register to vote, including those in Illinois. Mail in applications must be postmarked with today's date, which means you'll need to head to the post office in order to ensure that. To register in person in Cook County, head to the the Chicago Board of Elections, located at 69 W. Washington St., which will be open until midnight, or one of six Cook County clerk offices, which will remain open until 8 p.m. Voters must bring in two forms of identification to register in person, including one that provides a permanent address. A photo ID is not required. Those outside of Cook County should check with their local clerk's office for information on hours and voter registration information and requirements.
The Cook County Clerk's office will also provide grace period registration from October 10 through November 3. More infomation how to do that can be found here.