The Depression affected Steinbeck as war did Hemingway and exile did Nabokov: it changed his life and filled his work. The suffering of the wandering families and their oppression by larger, more powerful forces was a social crisis of widespread magnitude.
Their hardships and reality of life, from staying in dismal government camps, to losing family members, to not attaining work, showed that California and the road to it were not what they thought it would be.
And the associations of owners knew that some day the praying would stop. Today he is remembered because he told real stories about real people.
Like Steinbeck and everyone else in her community, she saw migrant families like the Joads arrive in drovesmany living in cardboard boxes in camps. It would appeal or annoy any generation, and it's got plenty of flaws — weak characters, flat style, blunt symbolism and melodrama, the list goes on.
So much of the dialogue today is about taking away food stamps or welfare, for example, and Steinbeck was a passionate voice for empathy.
Dust Bowl migration, the shaping of Californian identityand human connection to the environment are all deeply personal topics for Steinbeck.
Containing that contemporary story was a challenge … and one way that he met that challenge was to construct a family story that is punctuated by interchapters that tell a larger cultural and historical story.