I'm also in Illinois. Lunch is required to be started before the beginning of your 5th hour (counted from your actual clock-in time, not your scheduled time), and the clock restarts when you end meal.
If you clock in for the day exactly at 9:00 am, you have to be off the clock for lunch before 2:00 to avoid compliance. And then let's say you clock out at 1:45 and back in at 2:16. You have to be off the clock again before 7:16.
Your best bet, assuming you get to set your own meal and break schedule, is to take a break at about 11:30, lunch at 1:45, break at 3:45 and break at 5:30ish.