In the summer of 1969, a floating oil slick on the Cuyahoga River, which cuts straight through the city of Cleveland, caught on fire. The burn wasn’t large and wasn’t deadly or even extremely costly. It was also bound to happen: Nearby manufacturing industries had been polluting the river to the point where dead rats regularly floated in its waters. But this trivial fire did something far more significant: It became a status symbol for the state of America’s water — and triggered a massive outcry that led the U.S. to clean up its waterways.
