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Did Mrs. O'Leary's Cow Start the Great Chicago Fire?


Lithograph depicting Mrs. O'Leary and her cow, of Chicago Fire fame.

Lithograph depicting Mrs. O'Leary and her cow

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Question: Did Mrs. O'Leary's Cow Start the Great Chicago Fire?

Popular legend has long held that a cow being milked by Mrs. Catherine O'Leary kicked over a kerosene lantern and started a fire in a barn that spread into the Great Chicago Fire.

Was Mrs. O'Leary's cow really the culprit?


No. Mrs. O'Leary and her cow were not responsible for the Great Chicago Fire.

What really caused the massive blaze which destroyed much of Chicago in October 1871 were perilous conditions: a long drought during a very hot summer, and the fact that the city had been built almost entirely of wood.

However, Mrs. O'Leary and her cow did exist, and the legend about them being the cause of the fire endures to the present day.

The O'Leary Family and the Start of the Great Chicago Fire

The O'Leary family, immigrants from Ireland, lived at 137 De Koven Street in Chicago. Mrs. O'Leary had a small dairy business, and she routinely milked cows in a barn behind the family's cottage.

A fire did begin in O'Leary's barn at about 9:00 pm on Sunday, October 8, 1871.

Catherine O'Leary and her husband Patrick, a Civil War veteran, later swore that they had already retired for the night and were in bed when they heard neighbors calling out about the fire in the barn. By some accounts, a rumor about a cow kicking over a lantern began spreading almost as soon as the first fire company responded to the blaze.

Another rumor in the neighborhood was that a boarder in the O'Leary house, Dennis "Peg Leg" Sullivan, had slipped into the barn to have a few drinks with some of his friends. During their revelry they started a fire in the barn's hay by smoking pipes.

No one will ever know what really happened that night in the O'Leary barn. What isn't disputed is that the blaze spread. And, assisted by strong winds, the barn fire turned into the Great Chicago Fire.

Within a few days a newspaper reporter, Michael Ahern, wrote an article which put the rumor about Mrs. O'Leary's cow kicking over a kerosene lantern into print. The story took hold, and was circulated widely.

The Official Report Cleared Mrs. O'Leary and Her Cow

An official commission investigating the Great Chicago Fire heard testimony about Mrs. O'Leary and her cow in November 1871. An article in the New York Times on November 29, 1871, described Mrs. O'Leary's account of the night of the fire, and noted that she testified that she was in bed when the fire broke out.

The commission concluded in its official report that Mrs. O'Leary had not been in the barn when the fire began. The report did not state a precise cause of the fire, but mentioned that a spark blown from a chimney of a nearby house on that windy night could have started the fire in the barn.

Despite being cleared in the official report, the O'Leary family became notorious. While their house had actually survived the fire, they eventually moved from De Koven Street.

Mrs. O'Leary lived out the rest of her life as a virtual recluse, only leaving her residence to attend daily mass. When she died in 1895 she was described as "heartbroken" that she was always blamed for causing the Great Chicago Fire.

Years after Mrs. O'Leary's death, Michael Ahern, the newspaper reporter who had first published the rumor, admitted that he and other reporters had made up the story. They believed it would hype the story, as if a fire that destroyed a major American city needed any extra sensationalism.

The Legend of Mrs. O'Leary and Her Cow Starting the Great Chicago Fire Lived On

And while the story of Mrs. O'Leary and her cow isn't true, the legendary tale lived on. Lithographs of the scene were produced in the late 1800s, the legend of the cow and the lantern were the basis for popular songs over the years, and the story was even told in a major Hollywood movie produced in 1937, "In Old Chicago."

The MGM film, which was produced by Daryl F. Zanuck, provided a completely fictitious account of the O'Leary family, and portrayed the story of the cow kicking over the lantern as the truth. And while "In Old Chicago" may have been completely wrong on the facts, the movie's popularity and the fact that it was nominated for an Academy Award for Best Picture helped perpetuate the legend of Mrs. O'Leary's cow.

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