In what way did Steinbeck's own experience with migrant families influence him in writing his book?
During the Great Depression of the 1930s, many people from the midwest left the drought-ravaged land, often referred to as The Dust Bowl, and moved to California to live. California had a thriving agriculture and the farmers needed many people to work on their farms harvesting crops. California also offered jobs working in manufacturing, shipyards and defense factories that were gearing up prior to World War II.
Steinbeck grew up in the Salinas Valley in California, so he was exposed to the diverse culture that eventually was established there by these huge migrations. He witnessed first hand the bedraggled "Okies" who piled out of dilapidated cars, dressed in rags, as depicted in The Grapes of Wrath. Many of Steinbeck's works are set in this part of the country and reflect the influence of agriculture. Further, Steinbeck's characters are often common, low to middle-class people - farm workers, laborers, etc. Some members of Congress denounced Steinbeck's depiction of "Okies" in the novel Grapes of Wrath as being exaggerated.
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Steinbeck lived in Salinas Valley, California and had the opportunity to observe the transitional workers that migrated into California. He often took political stands in his work buy demonstrating the mistreatment of the outsiders or the ordinary man in his books. In the book The Grapes of Wrath, he witnessed the anger that native Californian’s felt when the people moved into the territory.
While Steinbeck may have exaggerated his characters, he did not exaggerate the mistreatment that they had experienced. He used his writing abilities to show the world many truths of the lives of the migrant workers.