In Chapters 17 through 21 of John Steinbeck's The Grapes of Wrath, the reader is struck by several central aspects of the life of the migrant workers and the harsh reality of the world they have left and the one they are now traveling through. His characterizations and plot development are particularly effective in portraying life during the Great Depression.
Steinbeck most effectively draws the reader's attention to the continuing importance of family. Groups that travel the road, camp together for comfort and companionship, further emphasizing the need for family and community. Those who do not follow the rules are asked to leave.
Loss of family is seen poignantly in Noah's departure, Mrs. Wilson's impending death, Floyd's arrest and then Casy's, Connie attempting to leave Rose of Sharon, and ultimately, the death of Granma. Ma observes that "the family's fallin' apart."
Another central focus of these chapters is the distinction between the "haves and have-nots." The migrant workers are moving westward to escape the devastation of the Depression for what is now known as the "dust bowl," believing in the American dream—that the U.S. is still the "land of opportunity." However, at every turn, they are met with resistance, illegal and brutal treatment, fear, and resentment. The landowners who have descended from those who took land from others in California, now fear that the same will happen to them. The migrant workers are not trying to take anything, but the landowners arm themselves and try to squash people who are already disenfranchised.
Finally, Steinbeck more than effectively describes people who have lost everything, and live their days haunted by hunger, fear, loss and death. People like Ma and her family try desperately to hold tight to their hopes of a better life. Tom becomes increasingly angry at the injustices he sees visited upon his family and others, while Ma cautions him to take care and not violate the terms of his parole. In essence, Ma is trying to salvage what is left of her family: those directly related to her, and those they joined with on this trip. As the story progresses, this becomes more and more difficult.