Who started the great chicago fire?
October 8th 1871, Almost from the moment the fire broke out, various theories about its cause began to circulate. The most popular and enduring legend maintains that the fire began in the O'Leary barn as Mrs. O'Leary was milking her cow. The cow kicked over a lantern, setting fire to the barn.
Legend is a family's cow knocked over a lighted lantern; however, Catherine O'Leary denied this charge, and the true cause of the fire has never been determined. What is known is that the fire quickly grew out of control and moved rapidly north and east toward the city center.