The Grapes of Wrath
The Grapes Of Wrath, is a novel written by John Steinbeck, published in 1939. It chronicles the path of the Joad family from their Dust Bowl farm in Oklahoma to California, where they are confronted by poverty, hunger, and death. It is considered by many to be one of the great American novels, and one of Steinbeck's best works. This is Steinbeck's most famous novel, garnering the Pulitzer Prize for him in 1940 and propelling him to winning the Nobel Prize for Literature in 1962 (that prize did not cite a specific work).
The catchy title is from The Book of Revelation in the New Testament.
This book is not without controversy: it contains vulgar language and has been the subject of attempted removals from public schools and public libraries, most often by Christian parental groups. Also, it arguably contains socialist themes, vilifying big banks and promoting labor unions. For this reason, Stalin attempted to use the movie for propaganda purposes in the USSR. However, shortly after it's debut it was pulled because people in the USSR started to realize that even poor Americans could afford cars.
The exploitation of workers on California cannabis farms today is compared with the "Okies" portrayed in this novel.