The official site of Chicago Marathon is www.hardrock100.com . 16 (from 6 confederations) were the number of teams who competed in Chicago Marathon . 2005 is when Chicago Marathon was founded  . The venue for Chicago Marathon was Paris, XVIe,France . 28 from 28 nations were the competitors in Chicago Marathon . 18 events were there in Chicago Marathon . It was held in April 23–29
Chicago Marathon was held over a few days