imported post
You can only open carry in Illinois in unincorporated areas. You are not allowed to open carry in a vehicle. When transporting firearms they must be unloaded and broken down or not immediately accessible unless you have a IllinoisFirearm Owner ID card, then the law says you can have it unloaded and encased. This is what some Illinoisans refer to as "fanny packing", transporting an unloaded firearm in a case with a loaded magazine, usually on your person. FOID cards are normally only issued to Illinoisans, but you could try getting one. The cost is $5 for 5 years, to go to $10 ( in June I believe) for 10 years. They should return your check if you are turned down. It involves filling out a form, answering questions and a background check, and takes a month. The Illinois State Police website has the form it is
http://www.isp.state.il.us Be warned however that you may be arrested even with a FOID card, and home rule communities may have different local ordinances. In southern Illinois south of I64, basically south of St. Louis, I don't know of any that do. I know of nobody convicted of Unlawful Use of Weapons while "fanny pack transporting" that has been convicted however. Many in law enforcement are not knowledgeable about the law, so it is possible to be arrested.
You didn't mention what part of Illinois you would be traveling through but southern Illinois is much more gun friendly than the north east. Avoid the Chicago area if at all possible, even if you get a FOID card.