1935 – The Dust Bowl heat wave reaches its peak, sending temperatures to 109°F (43°C) in Chicago, Illinois and 104°F (40°C) in Milwaukee, Wisconsin
. The Dust Bowl, also known as the Dirty Thirties, was a period of severe dust storms that greatly damaged the ecology and agriculture of the US and Canadian prairies during the 1930s; severe drought and a failure to apply dryland farming methods to prevent wind erosion (the Aeolian processes) caused the phenomenon. The drought came in three waves, 1934, 1936, and 1939–40, but some regions of the High Plains experienced drought conditions for as many as eight years. Extensive deep plowing of the virgin topsoil of the Great Plains during the previous decade had displaced the native, deep-rooted grasses that normally trapped soil and moisture even during periods of drought and high winds. Rapid mechanization of farm implements, especially small gasoline tractors and widespread use of the combine harvester, significantly impacted decisions to convert arid grassland (much of which received no more than 10 inches of precipitation per year) to cultivated cropland. During the drought of the 1930s, the unanchored soil turned to dust that the prevailing winds blew away in clouds that sometimes blackened the sky. These choking billows of dust – named "black blizzards" or "black rollers" – reached such East Coast cities as New York City and Washington, D.C. and often reduced visibility to a meter (about a yard) or less. Associated Press reporter Robert E. Geiger happened to be in Boise City, Oklahoma to witness the "Black Sunday" black blizzards of April 14, 1935; Edward Stanley, Kansas City news editor of the Associated Press coined the term "Dust Bowl" while rewriting Geiger's news story. The drought and erosion of the Dust Bowl affected 100,000,000 acres that centered on the panhandles of Texas and Oklahoma and touched adjacent sections of New Mexico, Colorado, and Kansas. The Dust Bowl forced tens of thousands of families to abandon their farms. Many of these families, who were often known as "Okies" because so many of them came from Oklahoma, migrated to California and other states to find that the Great Depression had rendered economic conditions there little better than those they had left. Author John Steinbeck wrote The Grapes of Wrath
and Of Mice and Men
about such people.