By: HISTORY.com Editors
Great Chicago Fire begins
On October 8, 1871, flames spark in the Chicago barn of Patrick and Catherine O’Leary, igniting a two-day blaze that kills between 200 and 300 people, destroys 17,450 buildings, leaves 100,000 homeless and causes an estimated $200 million in damages (more than $5.4 billion in 2026).
Legend has it that a cow kicked over a lantern in the O’Leary barn and started the fire, but other theories hold that humans or even a comet might have been responsible for the event that left four square miles of the Windy City, including its business district, in ruins. Dry weather and an abundance of wooden buildings, streets and sidewalks made Chicago vulnerable to fire. The city averaged two fires per day in 1870; there were 20 fires throughout Chicago the week before the Great Fire of 1871.
Chicago Fire of 1871
Find out what a cow has to do with the Chicago fire of 1871 in this animated tale of disaster and destruction in the windy city.
Despite the fire’s devastation, much of Chicago’s physical infrastructure, including its water, sewage and transportation systems, remained intact. Reconstruction efforts began quickly and spurred great economic development and population growth, as architects laid the foundation for a modern city featuring the world’s first skyscrapers. At the time of the fire, Chicago’s population was approximately 324,000; within nine years, there were 500,000 Chicagoans. By 1893, the city was a major economic and transportation hub with an estimated population of 1.5 million. That same year, Chicago was chosen to host the World’s Columbian Exposition, a major tourist attraction visited by 27.5 million people, or approximately half the U.S. population at the time.
In 1997, the Chicago City Council exonerated Catherine O’Leary and her cow. She had turned into a recluse after the fire and died in 1895.
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Citation Information
- Article Title
- Great Chicago Fire begins
- Author
- HISTORY.com Editors
- Website Name
- History
- Date Accessed
- October 21, 2026
- Publisher
- A&E Television Networks
- Last Updated
- October 02, 2026
- Original Published Date
- November 24, 2009
