One hundred and fifty years ago today the city of Chicago dodged a major bullet.

By Saturday October 7, 1871, Chicago was a flourishing prairie metropolis, one of the fastest growing cities in the nation. The expanding railroad network of the western United States – which had just recently reached the west coast – had its hub in the city by the shores of Lake Michigan, and eastern investors were pouring more funds into the city’s growth every day.

Population was growing. More than 1000 factories were churning out every product imaginable. Farms from the surrounding area kept the city’s seventeen grain elevators and countless stockyards and packinghouses busy around the clock.

To keep up with the need for more housing and more commercial structures, Chicago had seen a building boom in the years since the end of the Civil War. This massive expansion in construction was aided by the proximity of a seemingly limitless supply of lumber just a few miles to the north.

In order to feed the bustling city’s insatiable need for more and more wood, trees were being felled as fast as possible in Wisconsin and Michigan, loaded aboard steamships for the journey down Lake Michigan, then quickly unloaded onto Chicago’s docks and rushed to lumberyards. By October 1871 around two-thirds of the buildings in Chicago were made of wood – many of them with tar roofs.

It wasn’t just houses being slapped together as quickly as the boards could be acquired either. Businesses, gathering halls, bridges and even the city’s sidewalks were made of north woods lumber.

It had seemed like a good idea at the time.

Much of the city was built on reclaimed swampland and was prone to turn into a muddy mess when the rains came, so slightly elevated sidewalks just made sense. So did streets made out of pine blocks – nearly 57 of the city’s 88 miles of paved streets. Masonry and iron were expensive and using those materials took more time to build than planners in the fast-growing city believed they could spare. Even the fancy brick and marble buildings downtown and the brand new “fireproof” water works had roofs made of wood.

Not everyone was blind to the danger. For years the chronically understaffed, underequipped and underappreciated Fire Department had warned a succession of mayors of “the grave defects of the manner in which our city is being built.” Others took note of the slapdash manner in which many of the city’s most important structures were built. The Chicago Tribune called some of the hotels and tall buildings downtown “firetraps pleasing to the eye.”

In 1868 the Board of Police, which oversaw the Fire Department, warned that buildings in the city were being built with only monetary cost in mind, not safety. “In many cases, ornament is substituted for strength, and safety is sacrificed for cheapness.”

The 185-strong fire department urged the city to enforce its building codes, to require metal roofs on buildings like hotels and invest more in firefighting infrastructure like hydrants and water mains, but it was to no avail.

However, the city was not entirely without a plan. Most building owners had fire insurance, which they believed was all the attention they needed to show to that concern. The fire department consisted of 29 companies, 17 of them equipped with steam engines, pulled by horses, to respond to fires. Atop the fireproof courthouse, which was the tallest building in the city, a sentinel gazed out over the rooftops at all hours of the day and night, looking for the first signs of flames in the distance.

Upon spotting a blaze, the watcher would shout the word downstairs to the operator of the city’s alarm system who would use the telegraph to send the nearest fire company racing to the scene. As an added measure the courthouse’s bell would be rung repeatedly to help spread the alarm. Each firehouse in the city had a similar lookout, but they stood atop much smaller buildings with more limited vistas.

Just after the Civil War the Chicago had put in place a system of more than 150 fire boxes throughout the city which would allow anyone spotting a fire to throw a switch in the box and instantly summon the fire department.

So far this system had worked. Fires broke out all the time, but the network of watchers and alarms had allowed firefighters to reach each scene before the fire could spread and wreak much havoc.

Now it would be put to the test.

The arrival of the decade of the 1870s had brought with it unusually dry conditions. The year 1870 had seen a drought strike most of the Midwest, and it was not uncommon for newspaper readers to come across stories of fires which had struck rural areas to the west or forests to the north. Some of these fires spread to nearby small towns with tragic consequences. Chicagoans read these stories, but placed their confidence in their insurance brokers and their hard-working but overwhelmed fire department.

By the fall of 1871 things had reached a critical juncture.

Ruins in Chicago after a fire in 1870 
Sometime around July 4 it stopped raining. Between Independence Day and the first weeks of fall, only one inch of rain had fallen in Chicago. What had not stopped was the wind: howling in from the dry, overheated prairies. As autumn settled in, Chicago’s pinewood structures dried out. Leaves fell from the trees and were swept up by the wind until they hit an obstruction, like a wooden fence, a wooden building or an elevated wooden sidewalk, forming into piles when the wind could push them no farther. Families in the city prepared for winter by stocking their barns with full loads of hay for the animals, kerosene for their heaters or coal for their stoves.

Historian Alfred T. Andreas later wrote, “nature had withheld her accustomed measure of prevention, and man had added to the peril by recklessness.”

On Saturday night October 7, noted moralist orator George F. Train spoke to an assembly at Chicago’s Farwell Hall. He closed his remarks with an ambiguous but terrifying warning.

“This is the last public address that will be delivered within these walls! A terrible calamity is impending over the city of Chicago! More I cannot say. More I dare not utter,” he said before leaving the stage. But what did he mean?

A less apocalyptic, but more precise warning was sounded by the Chicago Tribune the next morning. A writer noted that “the absence of rain for three weeks…left everything in so flammable a condition that a spark might set a fire which would sweep from end to end of the city.”

It wasn’t just Chicago where these conditions existed. That very weekend the deadliest fire in American history swept through the area around Peshtigo, Wisconsin, killing as many as 2000 people. On the other side of Lake Michigan, Holland and Manistee, Michigan, were also swept by fire. To the south, Urbana, Illinois, would battle its own conflagration that weekend.

Much later the Chicago historian Joseph Kirkland described the conditions that Saturday thusly: “The feast was spread, and only awaited the fiend.”

That day, October 7, 1871, it seemed the fiend had come for the feast. After a week in which there were twenty separate fire calls, the city’s firefighters were once again summoned. The fire alarm bell in the courthouse rang at around 10 p.m. and fire companies raced out to a fire at the Lull and Holmes mill at 209 S. Canal Street, just south of downtown. By the time they arrived, the fire was raging along a part of the Chicago River waterfront known as “Red Flash” because of its known susceptibility to fire. It was fueling itself on the wooden buildings but also on a supply of coal on one of the wharves.

More and more companies responded to the call, and the battle lasted through the night and into the next afternoon. After a fierce and bitter battle, firefighters were able to contain the blaze to a four-block area and eventually extinguish it, but not before it did almost $1 million in property damage. It had been one of the worst fires in Chicago’s history up to that time.

But the victory had come at great cost. The entire fire department had been drawn into the battle. Engines and hoses were damaged. Firefighters were injured. The dwindling supply of water available for firefighting was almost tapped out. Worn out firefighters headed back to their firehouses for some desperately needed rest and to repair their equipment and replace their singed clothing.

Mrs. O'Leary's Residence 
The city breathed a sigh of relief as the last smoldering embers of the fire by the river were extinguished.

The bullet had been dodged. The fiend had not come for the feast after all. The city was safe.

And according to legend it was right about that same time, at 137 DeKoven Street on the city’s west side, that Catherine O’Leary picked up a lantern and walked out to the barn to milk her cow.