This is 99% invisible. I'm Roman Mars. The Chicago River used to be completely filthy.

I mean, it's not great now, but it used to be so much worse. The people of Chicago were doing disgusting things to it.

Essentially using the river as a sewer and all of Chicago's waste, human waste, and also as a stockyards grew up in the city, all of the animal waste was

dumped into the river and it was said that the river was so thick with filth that a chicken

could walk across it without getting her feet wet. with

that a chicken could walk across it without getting her feet wet. That's Elizabeth Colbert,

author of the new book Under a White Sky.

What needs to be also understood is that the Chicago River

in its original incarnation

it flowed eastward into Lake Michigan which was and still is Chicago's sole

source of drinking water.

So to fix this problem, the city of Chicago

carried out a massive project.

They reversed the river and sent the sewage water

into the Mississippi.

When this enormous construction project was completed, which was, it was one of the most enormous

construction projects of its era, there was a facetious headline in the New York Times that said something like

water in the Chicago River resembles liquid again. By the way if you want to know more

about how it's even possible to reverse the river we did a whole story about it.

Episode 86, it's a good one.

Anyway, the river reversal was a big success.

Chicagoans had a reliable supply of clean drinking water.

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