The teen-aged brother of Tom is a social young man, his primary concerns being girls and cars. He admires Tom, particularly because he has been in prison, and until the family reaches California, strives for his older brother's approval. Because he had "driven truck" for a year, Al is given the responsibility of maintaining the family's automobile, a responsibility he takes seriously. Although a pleasant, well-meaning young man, he lacks Tom's sense of morality and accountability. For example, while Tom is investigating the commotion outside the gates of the peach ranch, Al's main objective is searching out available young girls. Although Al never seems to experience a spiritual conversion on the scale of his brother Tom, he does grow in ways that are significant to Steinbeck's message of social change. His engagement to Aggie Wainwright at the close of the novel indicates a joining of the Wainwright and Joad families, an act symbolized by his taking down of the curtain separating the two halves of the boxcar. This joining is only temporary, however, as Al will be left behind when the Joads abandon the boxcar. Aggie and Al, in their desire to create a non-agrarian life outside of their families, represent the ability to change that Steinbeck feels is necessary for the survival of the migrant worker.
Granpa is a colorful old character — earthy, lecherous, and full of life. He is somewhat of a child, shouting and behaving outrageously, bragging about what a "heller" he was, and swearing. He forgets to button up his trousers after using the bathroom. At the beginning of the story, Granpa is the one character who seems completely ready to embrace a new life (he speaks of crushing grapes and letting the juice run down his face). But ironically, when it is time to depart, he refuses to leave the land on which he has lived his entire life. Granpa has to be drugged to be taken off the property and is never again completely conscious after the family leaves. When the family makes camp at the end of the first day of travel, he has a stroke and dies.
Equal to Granpa in crotchetiness and spirit, she loves to argue with him. She is comically spiritual — an example of the absurdity of organized religion. She shouts "PRAISE GAWD" every time Casy pauses during grace, even though it's not grace in the conventional sense. Her clinging to her spirituality is seen most poignantly at Granpa's death when she frantically demands of Casy, "Pray, goddam you." After Granpa's death, she retreats into a somnambulistic state, becoming increasingly incoherent. She dies during the Joads' nightlong trek across the California desert and is buried a pauper when the family reaches Bakersfield.
Uncle John Joad
Pa's older brother, John has, for many years, carried the responsibility for the death of his young wife during her first pregnancy. Midway through her pregnancy term, she had complained of stomach pains. John refused to get a doctor, because he was sure she had simply "Et too much." By the next afternoon, she was out of her head with pain and soon died from a burst appendix. Wracked with remorse for this "sin," John alternates between drunkenness and widespread acts of haphazard charity. He lives with the burden of this individual sin, which seems to become overwhelming during times of family crisis.
At 12 years old, Ruthie is poised between childhood and adulthood. She is often childish and domineering, particularly of her younger brother. Her bossy attitude makes it difficult for her to make friends in the various camps the family stops in. In fact, during a fight with another child, she spills the information that her brother Tom is hiding nearby because he has killed a man.
Ten-year-old Winfield is the youngest member of the Joad clan. He and Ruthie seem the least affected by the leaving of the family home. Winfield is, for the most part, a typical child: boisterous and playful.
The eldest Joad son is quiet and strange, but not retarded, as he would seem at first glance. He can read, write, and figure as well as the others, but he is oddly detached, even from his family. His role in the family is an understated one. When the family camps at the Colorado River, Noah decides that he can't leave the water and becomes the first member to consciously abandon the family.
Ivy and Sarah (Sairy) Wilson
The Joads meet this migrant couple on the first night of their journey. Looking for a place to camp, they roll up next to the Kansas couple's disabled automobile. When Granpa dies of a stroke, the Wilsons offer their tent space and quilt. They even tear a page from their own bible to be buried with Granpa. In return, Al fixes their car, and the two families decide to travel to California together. They remain together until the California desert when Sairy tells her husband that she is too ill to continue. The Joads leave the couple, knowing that she will not survive. The Joads' relationship with the Wilsons is a microcosm of the larger picture of migration, a look at the strength derived from unity in action. Their communal way of life is amplified in scope at the government camp at Weedpatch.
The Wainwrights are another migrant family looking for work in California. They share a boxcar with the Joads on the ranch where they pick cotton. Like the Wilsons, the Wainwrights represent the necessity of working together to form one community in order to survive. During the rains, Mrs. Wainwright helps Ma deliver Rose of Sharon's stillborn baby, and Mr. Wainwright helps Pa to build the embankment to stem the flood. Forced to drop familial boundaries, the Joads learn to accept help as well as to give it. When Al becomes engaged to the Wainwright's daughter, Agnes, he tears down the cloth separating the two halves of the boxcar, symbolically creating one family.