The Chicago fire: an unknown spark in a wooden city
The Chicago fire began on October 8, 1871, in the barn behind Patrick and Catherine O'Leary's home on DeKoven Street. Its precise cause remains unknown. The city's Board of Police and Fire Commissioners found no evidence that anyone had entered the barn after nightfall and accepted that the O'Leary family had been asleep. A cow overturning a lantern became the familiar explanation, but the investigation never established that scene. The destruction that followed involved a far larger combination of weather, combustible construction and failures in the city's defenses.
Chicago had grown to 298,977 people by the 1870 census. Wooden buildings accommodated much of that growth, while wooden sidewalks and bridges helped residents cross muddy streets. Roofs, fences, outbuildings and supplies of lumber added more combustible material. The summer and early autumn of 1871 had been exceptionally dry. Between July 3 and October 8, only 3.70 inches of rain fell. Strong winds from the southwest then carried burning material from one structure to the next, allowing the blaze to outrun firefighters working at its edge.
Before the Chicago fire, the department was already tired. Firefighters had worked through a major blaze on Saturday night and into Sunday afternoon before the O'Leary barn caught fire that evening. The commissioners later reported that the first central alarm pointed companies toward a location about a mile beyond the actual fire. One hose company had independently spotted the flames and began moving before the alarm sounded. By the time engines reached the neighborhood, several buildings were already burning. Reinforcements had to travel from more distant stations while wind scattered embers over their heads.
The Chicago fire crossed the South Branch of the river through airborne burning material. The gasworks and the courthouse were among the structures lost. At the waterworks, the pumping installation itself had a wooden roof and inadequate protection against fire. Once it burned, the city's water supply failed. Engines could still obtain water near the river, but damaged equipment and lost hose restricted how far they could carry it. The department's crews continued working while many of their own homes were being lost to the fire and their families were seeking safety.
By October 10, the fire had consumed roughly 18,000 buildings and about $200 million in property. Approximately 100,000 people had lost their homes. The burned district stretched about four miles, with enormous losses in the North Division. Yet much of Chicago's industrial base survived outside the devastated area. Important rail infrastructure also remained, even where downtown depots had burned. The O'Leary cottage itself survived in front of the ruined barn. Insurance provided uneven relief: company failures reduced payments, and poorer households often lost both possessions and employment.
Accusations against Catherine O'Leary spread while the city was still burning. Newspapers supplied a vivid barnyard explanation before investigators had finished their work. Catherine operated a small dairy business to help support her family. In the stories that followed, a hardworking woman in her early 40s was sometimes transformed into an elderly drunk or a resentful welfare recipient. Anti-Irish and anti-Catholic prejudice helped make her a convenient person to blame. The family's sworn testimony and the absence of evidence against her did little to stop the tale's circulation.
Even later claims about inventing the story were complicated. Reporter Michael Ahern boasted in 1911 that he and two colleagues had fabricated it. Another journalist subsequently said he had ghostwritten that recollection under Ahern's name. Rumors about a lamp, a party in the rented front portion of the cottage and other possible causes accumulated over the years. The commissioners had already considered the possibility of a chimney spark or human action, but could not determine which had started the barn fire. No later theory supplied a generally accepted solution.
The official investigation instead drew attention to the city's vulnerability. Its recommendations concerned construction, roofing, hydrants, pumping facilities and the distribution of firefighting resources. The commissioners argued that safer buildings around the starting point might have contained the blaze before it crossed the river. They also criticized dependence on a single pumping installation and proposed additional water sources. These were changes to an entire urban system. The disaster's scale could not be explained simply by assigning a name to the first person near the barn.
Rebuilding proceeded rapidly. Chicago's population reached 503,185 in 1880, and exceeded a million by 1890. The barnyard legend also found new life in songs, illustrations, commemorations and films. In the early 1960s the city placed its new fire academy on the block where the disaster began. In October 1997 the City Council's police and fire committee held a tongue-in-cheek hearing at the Fire Academy, which stands on the site of the O'Leary cottage, and it ended in the official exoneration of Catherine O'Leary. The Chicago fire's starting place remained identifiable, while its initiating spark remained unresolved.
- Chicago History Museum and Northwestern University, The Official Report — greatchicagofire.org
- Chicago History Museum and Northwestern University, The O'Leary Legend — greatchicagofire.org
- Chicago History Museum and Northwestern University, The Ruined City — greatchicagofire.org
- U.S. Census Bureau, History and the Census: 1871 Great Chicago Fire — www.census.gov