Many states: longest drought of 20th century. Peak periods were 1930, 1934, 1936, 1939, and 1940. During 1934, dry regions stretched solidly from N.Y. and Pa. across the Great Plains to the Calif. coast. A great “dust bowl” covered 50 million acres in the south-central plains during the winter of 1935–1936.

DamWorst United States DisastersEarthquake
Worst United States Disasters