Dust Bowl (1930s)

The Dust Bowl — a decade of severe drought and soil erosion across the American Great Plains caused by over-farming, poor agricultural practices, and cyclical drought — displaced 3.5 million people (Steinbeck's "Okies") in the worst human migration in American history. The disaster demonstrated for the first time that industrial-scale agriculture could permanently damage the land, and it drove the creation of federal soil conservation programmes and the New Deal policies that reshaped American governance.