Chicago Fire of 1871 Leave a Comment / Time Era 1800's / By S. E. Davis View of the devastation caused by the Chicago fire of 1871. — Image by © Bettmann/Corbis The aftermath of the Great Chicago Fire of 1871. Illustration of Chicago Fire: How it started. Mrs. O’Leary’s cow upset an oil lamp. Color image of hundreds of people scurrying away as flames ravage the city Hundreds of people hurrying away as flames ravish buildings Map of Fire