Illinois hotels you can book at 18
At 18, being told your Illinois hotel requires guests to be 21 or older can mean searching for another room after you've arrived. If your visit is to one of the cities below, you have 18+ hotels to consider without changing your destination.
10 hotels
Chicago
1 hotel
Joliet
2 hotels
Naperville
Union Station or a suburban Amtrak stop
Naperville lies west of Chicago, on Amtrak's California Zephyr, Southwest Chief, Illinois Zephyr and Carl Sandburg routes. If your visit is to Naperville, you can get off a Chicago-bound train there and keep your hotel search in that city. Continuing to Chicago Union Station would leave you with an unnecessary trip back out.
Joliet is southwest of Chicago and has Amtrak stops on the Texas Eagle and Lincoln Service routes. Neither route serves Naperville. If you're visiting Joliet on either train, you don't need a Chicago room simply because you're arriving by rail.
If your itinerary includes an overnight change between the California Zephyr and Texas Eagle, focus on Chicago hotels. Both trains serve Union Station, while neither Naperville nor Joliet has both services. A Chicago hotel avoids adding a suburban trip just for the night between those trains.
Illinois' smoking ban has a hotel-room exception
Illinois lets hotels and motels designate up to 25% of rooms rented to guests as smoking rooms. Local rules and hotel policies can be stricter, but the state's public smoking ban doesn't make every guest room nonsmoking. If you need a nonsmoking room, reserve that room type.
A smoking room doesn't become a nonsmoking one just because you won't smoke in it. The hotel can make it nonsmoking, but the change has to be permanent. A nonsmoking room reservation alone doesn't tell you whether smoking is allowed in the hotel's other guest rooms.