London Velopark (BMX, track),Chicago, Illinois, United States were the venues of Chicago Marathon . Chicago Marathon was established on 1891; 128 years ago (1891) . 18 from 18 nations were the competitors in Chicago Marathon . It was held in 28 July – 9 August . The official site of Chicago Marathon is www.hardrock100.com . 16 (from 6 confederations) were the number of teams who competed in Chicago Marathon
The sport Chicago Marathon has more than20 contestants  from 18 nations