“LIKE A SNOWSTORM LIT BY COLORED FIRE”

Hardly any rain had fallen on Chicago for months, and the drought was getting worse. Over the 22 days leading up to October 8, 1871, it had rained only once — a measly 0.11 inches. “Under the burning sun for so many weeks, the whole city became virtually a tinderbox,” recalled William Bross, one of the Chicago Tribune’s owners.

A mere 35 years earlier, Chicago had been a frontier outpost with a few thousand inhabitants, but now it was the commercial metropolis at the heart of the Midwest, growing at an astonishing pace as it drew people from around the country and from Europe, mostly German and Irish immigrants.

By 1870, it was the United States’ fifth-largest city, with a population of 300,000. And for the most part, it was made of wood. “Lumber was cheaper than brick and was more easily procured and more rapidly handled,” the Tribune would observe in 1872. “In a city where time was everything and durability was not a matter much considered, street after street was lined with wooden buildings.”

Forest and prairie fires were frequent in 1871 across a vast swath of the country’s northern regions, from the Rocky Mountains to upstate New York. During the first week of October, the Chicago Fire Department fought more than two dozen fires, wearing out the city’s approximately 190 firefighters and their horse-drawn equipment. They had 17 steam fire engines — three of which were out for repairs — along with four hook-and-ladder wagons and six carts that carried reels of fire hose.

Nearly the entire department spent the night of Saturday, October 7, battling a blaze that burned down four square blocks just west of the Chicago River’s South Branch and north of Van Buren Street. Many firefighters were still working at the smoldering site Sunday afternoon. Some had been on the job for 18 hours. “The men were exhausted, and some of the engines were in bad condition,” said Robert A. Williams, who’d been Chicago’s chief fire marshal since 1868. “The supply of hose was inefficient.” They’d barely had a chance to rest when another fire broke out Sunday night, in a barn half a mile south of Saturday night’s burning. After that, as firefighter Leo Meyers recalled, “everything went wrong.”

Over the next 30 hours, that fire would grow and grow, roaring across roughly three square miles in the heart of Chicago, killing hundreds of people and destroying 17,450 buildings — causing more property damage than any fire before it in America. As Chicago marks the disaster’s 150th anniversary, the fire remains the most famous event in the city’s history.

This is the story of the Great Chicago Fire, as told by people who lived through it. Their words are from letters, memoirs, oral histories, newspaper articles and books of the time, and testimony at a city inquiry in 1871 (which Richard F. Bales transcribed for his 2002 book on the fire and donated to the Chicago History Museum). The quotes have been lightly edited for clarity and length; language of the era has been left intact.

“Kate, the barn is afire!”

Patrick and Catherine O’Leary lived with their four children on DeKoven Street just east of Jefferson Street, an area where most of the residents were Irish or Bohemian. Now considered the South Loop, in 1871 this was part of the West Side or West Division — as the city designated all land west of the Chicago River’s branches.

Joseph Edgar Chamberlin, 20, was a Chicago Evening Post reporter.

Chamberlin: That neighborhood had always been a terra incognita to respectable Chicagoans, and during a residence of three years in the city I had never visited it. The land was thickly studded with one-story frame dwellings, cow stables, pig sties, corn cribs, sheds innumerable — every wretched building within four feet of its neighbor, and everything of wood. Not a brick or a stone in the whole area.

It’s uncertain precisely how old Patrick and Catherine were in 1871, because the U.S. census and other vital records are inconsistent, but most documents indicate they were in their 40s. They’d come from Ireland about two decades earlier, at the beginning of the Irish Potato Famine, and Patrick found work as a laborer. He bought the lot on DeKoven Street for $500 in 1864. Two adjoining cottages stood on the property: The O’Leary family lived in back, and rented out the other to the McLaughlins, who were also Irish immigrants. The O’Learys sold milk, keeping several cows and a horse in a barn at their property’s north end, along an alley.

Patrick and Catherine O’Leary’s son Jim, who was 8 years old, was interviewed as an adult about that week’s events.

Jim O’Leary: The day before the fire — it was a Saturday — I helped the old gent put in some timothy hay in the loft above the cow shed. My part of the job was to stamp it down in the mow. I thought it was great sport.

His sister Katie, who was 5 in 1871, spoke decades later about that Sunday evening.

Katie O’Leary: Mother had put me to bed with the other children at 8 o’clock. She went to bed, too, and father followed a half-hour later. It was a hot night, and the sun had been blistering for weeks.

That evening, Catharine McLaughlin, 36, and her husband hosted a party for a relative who’d just arrived from Ireland.

Catharine McLaughlin: There was a greenhorn brother of mine there. The cousins and neighbors of mine came in to see him. My husband played two times on the fiddle, that was all. There was one, a brother of mine and another lady danced a polka. That is all that was played.

Catherine O’Leary: I knew they were not in bed, because I could hear from my own bedroom. Could hear them going on. There was a little music there.

Many stories were told about what happened next. Guests from the McLaughlin party supposedly entered the O’Leary barn and milked a cow, which kicked over a lantern. Or some men or boys went into the barn to drink, smoke, or gamble, or to hunt rats, inadvertently starting a fire. During an 1871 inquiry, the city’s Police and Fire Commission heard no testimony from anyone who’d been seen entering the barn, but that investigation was far from thorough. Daniel Sullivan, a 26-year-old Irish immigrant with a wooden leg, testified that he saw a fire in the barn around 9:20 or 9:25 p.m., when he was sitting on the other side of DeKoven Street.

Sullivan: I got up and run across the street and kept hollering, “Fire, fire, fire!” I couldn’t run very quick. I could holler loud enough but could not run. At the time I passed O’Leary’s house, there was nobody stirring.

I made right straight in the barn. I made at the cows and loosened them as quick as I could. I got two of them loose, but the place was too hot. I had to run when I saw the cows were not getting out. The boards were wet, my legs slipped out from me, and I went down. I stood