Question: was the great chicago fire started by a cow

Answer: No, The fire started at about 9:00 p.m. on October 8, in or around a small barn belonging to the O'Leary family that bordered the alley behind 137 DeKoven Street. The shed next to the barn was the first building to be consumed by the fire, but city officials never determined the exact cause of the blaze. There has, however, been much speculation over the years. The most popular tale blames Mrs. O'Leary's cow, who allegedly knocked over a lantern; others state that a group of men were gambling inside the barn and knocked over a lantern. Still other speculation suggests that the blaze was related to other fires in the Midwest that day.