Historians are unsure of what exactly caused the Great Chicago Fire of 1871, but legend says that it was a cow. The blaze started in the barn of Mr. and Mrs. Patrick and Catherine O’Leary, a poor Chicago family of seven. Mr. O’Leary worked as a laborer and Mrs. O’Leary sold milk from her cows. Little did the couple know that one of their cows would one day become the most famous cow in history.

Legend says that Mrs. O’Leary’s cow kicked over a lantern to start the massive fire. Even though it began in a barn, the flames were ferocious; the fire was completely out of control. It destroyed 3.5 square miles and $200 million worth of property, and killed 300 people. Rain began to fall two days later and helped put out the fire.

Don’t believe the legend? Others think Mrs. O’Leary had a motive behind starting the fire herself. The Chicago Tribute claims the city learned that she sold milk on the side and cut her off. This fire was Mrs. O’Leary’s vengeance on the city.

Do you know any other stories about how this fire started? Comment below and let us know!

Check out what else happened this week in history or learn more about taking your students on a field trip to Chicago