28 from 28 nations competed in Chicago Marathon . The sport has the official site www.hardrock100.com . 2005 is when Chicago Marathon was founded  . 18 events were there in Chicago Marathon . 16 (from 6 confederations) teams participated in Chicago Marathon . The venue for Chicago Marathon was Paris, XVIe,France . April 23–29 was when it was held
Chicago Marathon saw a competition between 18 squad 