Chicago Marathon

The Chicago Marathon (branded Bank of America Chicago Marathon for sponsorship reasons and formerly the LaSalle Bank Chicago Marathon) is a major marathon held yearly in Chicago in Cook County, Illinois, United States. Alongside the Boston, New York, London and Berlin Marathons, it is one of the five World Marathon Majors. Thus, it is also an IAAF Gold Label race. The October 7, 2012 running was the 35th anniversary of the race. The first race was held on September 25, 1977 under the original name the Mayor Daley Marathon, which drew a field of 4200 runners. The race has been held every year since, except in 1987 when only a half-marathon was run. It is among the fastest growing marathon road races in the world, due in part to its largely fast and flat course which facilitates the pursuit of personal records and world record performances. The race has achieved its elite status among marathons by developing relationship with sponsors who provide prize money to lure elite runners who have produced American and world record performances.

There is no qualifications required to participate in the Chicago Marathon, but only runners who finish within 6½ hours are officially timed. The race is limited to 45,000 runners on a first-come, first-served basis. Although the race has limited registration, exceptions include elite runners and charity representatives. Increasingly, local (e.g., Chicago's Children's Memorial Hospital), national (e.g., American Cancer Society) and global (e.g., Global Business Assist, British Red Cross, Asha for Education, World Vision) charities and humanitarian organizations encourage sponsored participation in the event as a means of fund raising.

The 2008 marathon featured a new sponsor name in Bank of America, (as Bank of America acquired LaSalle Bank in 2007). Some 37,455 runners completed the 2012 Chicago Marathon.