Darien, WI which is about 10 miles NW of Harvard, IL on US-14 has a Corn Festival on the Friday-Sunday after Labor Day weekend.
During the mornings (11am - 3pm) on Saturday and Sunday, they offer FREE roasted corn on the cob to all who make an appearance. You do not have to be a resident to participate and the only limit is the amount you can eat.
Darien Cornfest