Google is your friend.
I don't live anywhere near Chicago, but I can find the stores (as in true retailers you can physically go to) carrying Olympus DSLR's after a few clicks:
http://www.wolfcamera.com/search/Olympu ... al-cameras
http://www.calumetphoto.com/ctl?ac.ui.p ... ry=olympus
http://www.ritzcamera.com/search/Olympu ... al-cameras
P.S. America doesn't appear to have many dedicated camera retailers. Either you have Best Buy or some super specialist grandpa store selling camera antiques.