Hang on - under the IL “Human Rights Act” -- “As a general rule, you can use the restroom consistent with your gender identity. If confronted, you are not obligated to produce identification to prove your gender, and you are protected by public accommodations laws in Illinois.”
Which see: http://www.equalityillinois.us/issue/transgender/
IL has 99 problems, sure, but don’t lump us in with NC and MS.
Been there. Done that.