The most famous fire in American history happened in Chicago on October 8, 1871, but it's

not the fire that is so remarkable.

It's what happened afterwards.

To understand why we first need to know something about the city's history.

In 1840, Chicago was a small town of 4,500 souls.

It ranked 92nd in population in the United States, yet only three decades later by 1870,

but a year before the Great Fire, Chicago was closing in on a population of 300,000, making

it the fifth biggest city in America and the fastest growing city in the world.

What led to all this rapid growth?

In three words, location, location, location.

Chicago was near the center of the country and near where the waterways and railways met.

City historian Tim Samuelsen notes, it was a perfect place for anything and anyone to

get anywhere.

Timing had a lot to do with it too.

America was moving from a rural to an industrial power.

Chicago was right in the middle of the action.

Ironically, its rapid growth was almost it's undoing.

Chicago had to build and build quickly, and so they built it out of wood, explained

Sauer Marcus at the Chicago History Museum.

It was quick, it was easy, and it was cheap.

And as it turned out, very flammable.

By most accounts, the fire started on the city's west side, near the Decoven Street barn

...