Three characters emerge as the most important in thinking about and developing the central themes of The Grapes of Wrath:
Tom Joad: Recently released from prison for killing a man in an angry brawl, Tom rejoins his family as they are about to leave Oklahoma in search of a better life in California. Tom breaks parole to travel with his family. He and his mother emerge as the strongest members of the clan; Tom continually emphasizes the need to "put one foot in front of the other," day by day-the very method of coping with life that he learned in prison. Although he promises his mother he will try not to get angry again, so as to avoid landing in more trouble, he ends up killing the man who murders Jim Casy. Tom's eventual anger at the injustice and humiliation he, his family, and other "Okies" face leads him to leave the family and become a labor advocate, leading strikes and fighting in other ways for economic and social justice.
Jim Casy: A former Holiness preacher, Casy has abandoned his conventional faith in God for a newfound, deep faith in humanity. He sounds the dominant theme of the novel; namely, that true holiness is the universal human spirit in which all people participate (see "The Oversoul" in Theme Analysis). Casy is a martyr for his beliefs when, in California, his leadership of a labor strike at the Hooper farm costs him his life. His death serves to inspire Tom Joad to take up the cause of advocating for economic and social justice.
Ma Joad: Ma is, in Casy's words, "a woman so full of love" she can be frightening. Against all gender expectations of her day, Ma provides the moral and emotional center for the Joad clan. She is committed to caring for all people as she can (witness her inclusion of Casy when the family sets out for California) and, even though this conviction faces sore testing along the journey, Ma ultimately holds fast to the truth that true family is larger than biological relations. While Ma urges her parole-breaking son Tom not to get angry, she finds her own righteous (not self-righteous!) anger growing as her family faces more and more deprivation and humiliation. She learns-and, through her, readers learn-about the right use of anger in changing society, even if in small but significant ways (such as persuading Rose of Sharon to offer the breast milk produced for her stillborn child to a "stranger" dying of hunger at the novel's end).
Other significant characters in the novel include:
Grandpa and Granma Joad: are the oldest generation of the Joad family. As Casy observes when Grandpa dies, their fate is tied to the fate of the land. When the land is taken away from them, their reason for living is taken away as well. They do not live to see the family reach the "promised land" of California.
Pa Joad: is a strong man who "figures" as hard as he can how to handle the family's problems (a recurrent motif in the novel), but his "figuring" ultimately yields to Ma's decisive actions. This sea change in gender roles of the time is seen perhaps most clearly in the final chapter, when Ma makes the decision that the family must seek a dry place to stay. Throughout the book, Pa comments that Ma's increased assertiveness represents a fundamental change in the world he knows.
Al Joad: is Tom's younger brother, who-like a younger version of his grandfather-has something of the "hellcat" about him. He is interested in cars and girls, and not even the Great Depression can curb his curiosity about these subjects! Despite some mistakes, Al proves dependable and good-hearted, and remains with his family until the end of the novel, when he stays behind to marry Aggie Wainwright, a fellow migrant he has met and with whom he has fallen in love (and, readers are left to wonder, may have impregnated-perhaps providing a note of hope that counterbalances the loss of Rose of Sharon's child and assures us that, as Ma has earlier said, "the people . . . [will] go on").
Rose of Sharon: (called "Rosasharn" throughout the book) is the eldest daughter of the Joad family. She is expecting a child with Connie Rivers, who announces big plans to study electronics at night in hopes of giving his family a better life than that of farm work. When it becomes apparent, however, that life in California will offer him no such opportunity, Connie abandons Rose and her family. Initially (and understandably) devastated, Rose of Sharon ultimately comes to understand-as does her mother, as does her brother, as does Jim Casy-that she is not the center of life; rather, humanity as a whole is. Her act of breastfeeding the dying man at the novel's end illustrates her acceptance of this truth.
Uncle John: accompanies the Joads on their trek to California. He brings with him the personal demons he has never been able to conquer. He struggles with alcohol, and with feelings of sin, the entire length of the book. Unlike Casy or Tom, John is not able to accept the whole of his life, good and bad, for what it is without judgment.