In the early 1900s, thousands of settlers moved to the Great Plains to start farms. The land was covered in thick prairie grass that had grown there for thousands of years. The grass roots held the soil firmly in place, even during dry spells. But the farmers plowed up the grass to plant wheat and corn. At first, the crops grew well because there was plenty of rain.

Then, in 1931, a terrible drought hit the Great Plains. Without rain, the crops dried up and died. With the prairie grass gone, there was nothing left to hold the soil down. Strong winds wore away the bare earth — a process called erosion — and picked up the loose, dry dirt to create enormous dust storms. Some storms were so large they blocked out the sun and turned day into night. People called them "black blizzards."

The dust storms destroyed what was left of the farms. Soil piled up against houses and buried fences. Animals and people got sick from breathing the dust. Without crops to sell, farm families had no money for food. Banks took away farms when families could not pay their loans.

By the mid-1930s, hundreds of thousands of people gave up and left the Great Plains. This migration west sent families packing everything they owned into old cars and trucks and driving to California, hoping to find work. The Dust Bowl showed how human actions and natural events can combine to create a disaster that changes the lives of millions.