Extensive farming combined with severe drought caused the Dust Bowl in the 1930s. Deep plowing on the Great Plains killed the natural grasses that kept soil in place, and the topsoil turned to dust and blew away. Tons of soil were blown off barren fields and carried in storm clouds for hundreds of miles, creating one of the most disastrous ecological events in U.S. history.
Between 1930 and 1940, severe dust storms, or “black blizzards,” reached heights of 10,000 feet, blowing cars off the road and blocking out sunlight. At times, the clouds blackened the sky all the way to New York City, and much of the topsoil was deposited in the Atlantic Ocean. An estimated 2.5 million people were displaced and millions of acres of farmland became useless, intensifying the economic impact of the Great Depression.