Catherine O'Leary is often associated with the Great Chicago Fire of 1871. She was a dairy farmer who owned a barn where the fire is believed to have started. The exact cause of the fire remains unclear, but it is commonly thought that a cow kicked over a lantern in her barn, igniting the blaze. Despite her connection to this historical event, O'Leary was not responsible for the fire. The disaster led to significant changes in fire safety regulations and urban planning in Chicago. O'Leary's name has become synonymous with the fire, but she lived a quiet life after the incident.