The Fire That Was Not the Cow's Fault

The Great Chicago Fire began at approximately 8:45 on the evening of Sunday, 8 October 1871, in or immediately adjacent to a small wooden barn at the rear of 137 DeKoven Street, on the southwest side of Chicago. The barn belonged to an Irish immigrant family named O’Leary. Over the following thirty hours the fire would burn approximately ten square kilometers of the central city, destroy seventeen thousand five hundred buildings, leave roughly one hundred thousand people homeless, and kill approximately three hundred. The exact starting point inside the O’Leary property, the precise sequence of the first few minutes, and the identity of the person or persons present when the fire began have never been definitively established.

What has been definitively established is what did not start the fire. The story that Catherine O’Leary’s cow kicked over a kerosene lantern while being milked at 9 p.m. on a Sunday evening — the version every American schoolchild was taught for most of the twentieth century — is fabricated. The fabrication was the work of a Chicago Tribune reporter named Michael Ahern, who covered the fire as a young man and, in 1893, twenty-two years after the event, gave an interview to a colleague in which he admitted he had invented the cow detail to make his original story more vivid. He had no actual evidence that Mrs. O’Leary or her cow were anywhere near the barn at the relevant time. The fabrication is, by some measures, the most successful piece of nineteenth-century American journalism — successful in the sense that the false story it created has outlived almost every accurate news report of the period.

What actually started the fire is genuinely uncertain. The two leading candidates, both supported by contemporary testimony, are an act of human carelessness (probably involving a man named Daniel “Peg Leg” Sullivan, a one-legged drayman who was the first person to give testimony about the fire’s start) and a flaring failure of a wood-burning stove in the small alley adjacent to the O’Leary property. The Chicago Board of Police and Fire Commissioners conducted an investigation in late 1871 that interviewed several dozen witnesses and produced a detailed report concluding that the proximate cause of the fire could not be determined from the available evidence. The Commission specifically exonerated Catherine O’Leary of personal responsibility. The exoneration received almost no contemporary newspaper coverage.

Why a fire could burn a quarter of Chicago

The conditions that made the fire catastrophic were structural and predictable. Chicago in October 1871 had been suffering through an extended drought — the summer rainfall total of 1871 was the lowest of any year since reliable Chicago weather records had begun in the 1850s. The autumn winds had been steadily from the southwest for several weeks, blowing toward the city center. The city’s recent rapid growth — Chicago had quadrupled in population in fifteen years and had become the United States’ fourth-largest city — meant that an enormous proportion of its building stock was new construction, often in cheap wood. By one contemporary estimate, two-thirds of the buildings in central Chicago in 1871 were wooden, and the streets and sidewalks were paved with wooden planks.

The Chicago Fire Department in 1871 was understaffed and exhausted. The department had responded to a substantial fire on Saturday, 7 October — a 16-block burn in a planing mill on the west side that had taken nineteen hours to extinguish — and most of the firefighters had been off-shift only since Sunday morning when the second fire broke out that evening. Equipment was damaged from the previous day’s response. Several of the steam pumpers had not been refilled. The crew rotations had not had time to reset.

The fire that began in or near the O’Leary barn around 8:45 p.m. on 8 October was not immediately a catastrophe. The first fire-watch alarm was sounded by Daniel Sullivan from the corner of DeKoven and Jefferson Streets at approximately 9:00 p.m. The alarm was misrouted by the watchman at the Courthouse — the watchman, William Brown, looked southwest from the Courthouse cupola, saw flames, and pulled the wrong fire-box, dispatching the responding companies to a location nearly two kilometers from the actual fire. By the time the misrouting was corrected and the correct companies were dispatched, the fire had jumped to neighboring properties.

It then jumped the Chicago River for the first time, around midnight, into the south branch’s industrial buildings. Burning embers, lifted by the southwest wind, were ignited at distances of up to a kilometer. The fire crossed the main branch of the river — a wide channel that was supposed to be a firebreak — sometime around 1:30 a.m. on 9 October. From there it reached the central business district.

By dawn on 9 October the central business district was burning. By the afternoon the fire was visible from ships fifty kilometers out on Lake Michigan. By the evening the fire had jumped the north branch of the Chicago River as well, and was advancing on the north-side residential neighborhoods. It burned through 9 October and into the early hours of 10 October before rain began to fall and the wind shifted. The last active flames were extinguished by approximately 11 a.m. on 10 October.

The Tribune, the cow, and the reporter who confessed

The Chicago Tribune’s coverage of the fire was, in the days immediately after, surprisingly careful. The newspaper had been founded in 1847 by Joseph Medill — by 1871 a substantial figure in American journalism and within months of being elected mayor of Chicago on a Fire Recovery platform — and Medill’s editorial standards in late 1871 were specifically directed at avoiding sensational claims about causes. The first two weeks of Tribune coverage attributed the fire to a combination of drought, wind, and an unknown initial source, and named the O’Leary family only as the property owners of the apparent origin point.

The cow story emerged from informal coverage, not the news columns. Michael Ahern, then twenty-eight, was a Tribune reporter who had been assigned to cover the West Side residential damage. He wrote a feature piece on the affected families that mentioned the O’Leary household in passing. In the feature, he added the detail — for color, by his own later admission — that Mrs. O’Leary had been milking her cow that evening when the cow kicked over a lantern. The detail had no factual basis. It was the kind of small narrative invention that nineteenth-century American newspapers routinely added to make stories more vivid, with the assumption that no one would notice or remember.

The detail was noticed. It was picked up by competing Chicago papers within a week and was repeated in the New York and Washington press by mid-November. By 1872 it had crossed the Atlantic and appeared in British coverage. By the late 1870s it was part of the standard American historical narrative of the fire.

Mrs. O’Leary herself spent the rest of her life — she died in 1895 — being approached by reporters who wanted her to repeat or confirm the story. She refused to talk to journalists after the early 1870s. Her family later reported that the cow story had ruined her social life in Chicago, where she lived for two decades after the fire as a recluse. She had not, as it happened, owned a cow that produced the milk for the small dairy business that had been her primary income; she had been a cow tender for a neighbor, but the relevant cow was not on her property on 8 October 1871 and was unconnected with whatever happened in or near the barn that evening.

Michael Ahern’s 1893 confession appeared in a Chicago newspaper interview in connection with an unrelated story. Asked about his coverage of the fire twenty-two years earlier, Ahern said: “I made it up. The cow was good copy.” The confession was reported in the Chicago papers but received almost no national coverage. The story Ahern had invented had by then taken on a life of its own and the confession did not slow it down.

The fire’s twin

The Great Chicago Fire began on the same evening as a separate and substantially more destructive fire two hundred and fifty kilometers to the north, on the Wisconsin-Michigan border. The Peshtigo Fire, named after the small lumber town at its center, burned approximately five thousand square kilometers of forest in northeastern Wisconsin and southwestern Michigan on 8 October 1871, killing somewhere between 1,200 and 2,500 people and destroying most of the surviving lumber towns of the western Upper Peninsula. The fire was driven by the same southwest wind, the same drought, and possibly the same atmospheric conditions that drove the Chicago fire. Some climatologists in subsequent decades have argued that both fires were ignited by the same atmospheric event — possibly a meteor shower, though the evidence for this is weak.

The Peshtigo Fire killed more people than the Chicago Fire, by a factor of approximately five. It destroyed more property in raw terms. It was, by most measures, the most destructive wildfire in American history.

It was reported, in the immediate aftermath, by no major newspaper. The Chicago Fire was happening at the same moment, in a major American city, with telegraph access. Peshtigo was a remote logging town. Almost the entire population was killed in the fire. There were no surviving witnesses to file the first dispatches. By the time the scale of Peshtigo became clear — about a week later, when investigators reached the area — the Chicago Fire had monopolized the national news cycle and there was no remaining bandwidth for the larger story.

The Peshtigo Fire is still, a century and a half later, the least-remembered American disaster of comparable scale. The cow that Mrs. O’Leary did not own and did not kick a lantern from is more famous than the deaths of two thousand people in a town nobody outside Wisconsin has heard of.