It was October 8, 1871 and the summer was a dry, parched one, with only about an inch of rain falling on the city of Chicago. The buildings were made of wood, the roads and sidewalks were essentially wooden planks over mud, and the bridges were made of wood. The whole city had become one dry tinderbox just waiting for a chance to go up in flames. The volunteer fire departments were replaced with professional firefighters who begged the city to provide more fire hydrants, make the water mains bigger, hire more men, and they also requested two fire boats to patrol the river and protect the bridges going in and out of the city. The fire department had also asked for a city building inspection department to point out which of the many four or five story buildings were poorly constructed and could become easy fodder for a fire. The city had refused all requests, fearing that the higher taxes may inhibit city and business growth.

The dry summer turned to autumn. Dead leaves and branches fell from trees and covered the already dry, brown grass. This was the perfect recipe for a devastating fire and all it needed was a catalyst. That catalyst became the O’Leary’s cow barn. Before the O’Leary barn fire, all 185 firefighters in the city had battled fires every day in October in the city, finishing they thought, after battling a blaze for 17 hours that burned four city blocks on Saturday, October 7 and finished up on Sunday morning, October 8. Sunday night, around 9 PM the watchman on duty spotted a fire and sent out the alarm as he located the conflagration on a grid. As the watchman continued to watch the fire, he realized that he directed the firemen about a mile away from the fire. The already exhausted firemen were merging in the wrong area.

It was Catherine O’Leary’s neighbor that saw the flames coming from the cow barn. It took less than an hour for a block of shanties to go up in flames. Fueled by the wind, the fire began moving north and east toward the city of Chicago. Soon, factories and warehouses caught fire causing the flames to get bigger and higher. The heat from the fire rose and forced cooler down, essentially making column of flames that looked like cyclones. These cyclones ripped roofs off of buildings and sent flaming chunks of debris flying across the river and by midnight, the South Side was in flames.

Another big chunk of flaming debris flew across the river and landed on a kerosene tanker and now the North Side was in trouble. The fire was so hot that it melted iron and steel, wood burned and stone was reduced to rubble or collapsed. People grabbed what they could from their homes and fled. On October 10, the morning brought rain and the flames were finally extinguished but not before at least 300 people died, 73 miles of road and 70,000 buildings were destroyed. As soon as the ashes settled, families began reuniting and the city began to rebuild.

Although the city ignored the fire departments’ warnings, and the river was so polluted with so much grease and oil that it caught fire and even though there was a hundred day or so dry spell prior to the fire, the blame was placed on poor Catherine O’Leary. Even though newspaper reporters had blamed one of her cows for kicking over a lantern and causing the devastating fire and later recanted their fabricated story, Mrs. O’Leary never recovered from the slanderous allegations and became a recluse, leaving her home only when she absolutely had to, until her death in 1895.