The sport has the official site www.hardrock100.com . It was held in 28 July – 9 August . 18 from 18 nations were the competitors in Chicago Marathon . The venue for Chicago Marathon was London Velopark (BMX, track),Chicago, Illinois, United States . Chicago Marathon was established on 1891; 128 years ago (1891) . 16 (from 6 confederations) teams participated in Chicago Marathon
Chicago Marathon event has celebrated it's  Ruby jubilee on 1951