John Steinbeck performed a rare feat for a writer of fiction. He created a literary portrait that defined an era. His account of the “Okie Exodus” in The Grapes of Wrath became the principal story through which America defined the experience of the Great Depression. Even today, one of the enduring images for anyone with even a passing familiarity with the 1930s is that of Steinbeck’s fictional characters the Joads, an American farming family uprooted from its home by the twin disasters of dust storms and financial crisis to become refugees in a hostile world. Not since Dickens’s portrayal of the slums of Victorian England has a novelist produced such an enduring definition of his age.

According to Penguin Books, which produced a very handsome series of paperbacks to mark the centenary of his birth this February, Steinbeck’s novels still generate a combined sale of around two million books a year. Originally published in 1939, The Grapes of Wrath remains a widely studied text in both high schools and universities, and the 1940 John Ford film of the book still enjoys healthy sales on videotape and frequent reruns on classic movie shows on cable television. The story that these various audiences hear goes like this:

Dust storms and bank foreclosures during the Great Depression forced a mass migration of hundreds of thousands of small landowners and sharecroppers from the American southwest, especially Oklahoma, Arkansas, and east Texas. Enticed by false advertising, impoverished farming families loaded their possessions