The Grapes of Wrath juxtaposes the Joad family’s experiences as they migrate from Oklahoma to California with intercalary chapters documenting the narrator’s wider perspective of the story’s social context. These chapters show the tenant farmers’ powerlessness against the landowners, who favor tractors over people; the rampant exploitation of migrants as they head toward the promise of abundant opportunities on uncorrupted land; the perseverance of and faith in humanity as the migrants help those in need; and the development of Steinbeck’s phalanx theory as individuals come together to create a more organized whole. The Joads’ trials act as a microcosmic representation of the injustice and misery being experienced by hundreds of thousands of Americans during this period.
The novel opens with a description of the dust storms caused by intense drought in 1930s-era Oklahoma. The storms are severe enough to block out the sunlight, leaving crops destroyed. A sense of nervousness hangs over the region as the powerless sharecroppers and their families struggle with the loss of their livelihoods.
On this desolate terrain, Tom Joad, on parole after spending four years in prison for manslaughter, hitchhikes back to his family’s farm with a trucker he meets outside of a restaurant. The trucker explains how times have changes since Tom has been away, with landowners and bankers using tractors to drive small farmers off the land.
Walking down a dirt road toward the farm, Tom sees preacher Jim Casy sitting near a shade tree. Casy tells Tom he had to give up preaching when he began to question his convictions about the nature of sin and God, brought on by the guilt he felt about sleeping with girls after his sermons. Some soul searching led Casy to conclude that sin and virtue do not exist: “There’s just stuff people do” (23). After Casy reveals his newfound beliefs—“maybe all men got one big soul ever’body’s a part of”—Tom explains how he came to commit murder (24). Drunk at a dance, Tom got stabbed during a fight with another drunk man. In self defense, Tom struck the man over the head with a shovel, killing him. Casy accompanies Tom to the Joad farm, which, to their surprise, they find completely deserted.
Tom and Casy notice that the Joad homestead has fallen into neglect. Muley Graves, a man recently displaced by the tractors, passes through the area. Muley explains that the Joads were kicked off their land and are staying with Tom’s Uncle John until they can gather enough money to make the trip to California, where work is said to be plentiful. Muley shares his meager dinner with Tom and Casy. When a police car approaches the farm, Muley advises them to hide lest they get arrested for trespassing. Muley shows Tom and Casy to a cave where they can rest for the night.
As Tom and Casy make their way to Uncle John’s farm the next morning, Tom tells a story about how John ignored his wife’s complaints of stomach pain, resulting in her death; John still feels extreme guilt over this. Tom and Casy arrive and Tom reunites with the family as they prepare for the move out west. Pa expresses concern that Tom may have escaped from prison, while Tom reassures Ma that prison hasn’t changed him for the worse. Reunions continue around the breakfast table with Granma, Grampa, and Tom’s older brother Noah. Also joining in: teenaged Al, who looks up to his older brother Tom, and Tom’s married, pregnant sister Rose of Sharon. The Joads’ two youngest children, Ruthie and Winfield, have gone into town with Uncle John to sell some belongings for traveling money.
Ma worries that California seems too good to be true. Grampa is optimistic that the trip will make him a new man. The family has a conference about their plans, and decides that Casy can join them on the trip. Muley stops by, turning down an invitation to come along but asking the Joads to tell his family that he’s fine if they encounter them. Grampa now refuses to leave, saying that he will live like Muley instead. When Grampa falls asleep, the family puts him in the truck. Driving away, the Joads give their land one last look.
While stopped for gas, the family’s dog gets hit by a car and is killed. Rose of Sharon worries that the shock of the accident might affect her pregnancy. After traveling through Oklahoma City, the Joads camp alongside Ivy and Sairy Wilson, a couple also on their way to California. Grampa has a stroke and dies; the family holds an impromptu funeral and buries Grampa themselves, even though it’s against the law to do so. With the Joads worried that their truck won’t make it over the hills and the Wilsons having car trouble, the families decide to travel together.
The Joads and Wilsons continue on through the Texas panhandle. Rose of Sharon tells Ma that she and Connie don’t plan to live out in the country anymore, with Connie wanting to manage a store in town. When the Wilsons’ car breaks down, Al takes the families to a nearby camp. With Al and Tom away looking for a car part, Casy has time to think about the number of people heading to California and he worries that there won’t be enough work for everyone. Coming back to camp, Tom and Casy find that the proprietor wants to charge them for the additional men and vehicle, so they decide to sleep in the car down the road. They meet a man who says the conditions in California caused his family to die from starvation.
The Joads and Wilsons continue through New Mexico and Arizona, finally making it to California’s border and setting up camp by a river before they have to cross the desert. They get more warnings about the harshness that awaits them from a father and son who are on their way home after failing to earn a living in California. Noah tells Tom that he is leaving the family and will try to live off the river. Meanwhile, a woman comes to the tent and wants to have a prayer meeting to send a sick Granma to a peaceful death; Ma makes the woman leave. The sheriff orders everyone to move along by the morning. Because Sairy is too weak to travel any farther, the Wilsons decide to disobey the sheriff’s instructions, staying behind and parting ways with the Joads. Ma has a fit when police stop the vehicle to inspect for plants and seeds. She claims that Granma is very sick and they don’t have time to stop. The men allow them to pass through uninspected and tell them where to find medical help. Ma later reveals that Granma was dead before they reached the inspection point, but she kept the news to herself until they’d made it through the desert.
After leaving Granma’s body at a coroner’s office, the Joads find a Hooverville—the name given to camps that pop up on the outskirts of towns—and meet Floyd Knowles, who explains how life works at the camp. He warns them about the low wages and working conditions, and tells them that being put on the blacklist will keep a man from finding work. Casy feels as if he should go his own way and stop being a burden on the family. Tom asks Casy to stay, explaining that jail has given him a sixth sense and he feels like something big is coming their way. Connie wonders if he should have stayed at home and gotten a tractor job; Rose of Sharon reminds him of his goals and says that she doesn’t want to give birth in a tent. As Ma cooks a stew for dinner, she notices that the children of the camp have gathered around her. Once her own family is fed, Ma leaves the rest of the food for the other children. A nicely dressed man drives into camp and offers the migrant people work in Tulare County. A wary Floyd tells the group not to work for anyone who cannot produce a license or guarantee a wage. Upon hearing this, a deputy named Joe gets out of the car and hassles the group, even trying to arrest Floyd on a false charge. Floyd punches Joe in the face and runs away; when Joe chases Floyd, Tom trips the deputy. Emerging from the crowd, Casy kicks Joe in the neck and renders him unconscious. Casy tells Tom he’ll take the blame for him as a way of repaying the family’s hospitality. After the incident, Uncle John feels guilty about keeping five dollars hidden away in case he needed alcohol. Pa, who knows that Uncle John feels a lot of pain over his wife’s death, takes three dollars and gives Uncle John permission to use the remaining money for alcohol. Connie, meanwhile, is nowhere to be found, upsetting Rose of Sharon. While the family gets ready to move again, Tom goes in search of Uncle John, telling the shopkeeper that they’re heading south, in case Connie comes back. Finding Uncle John drunk in the woods, Tom knocks him out and carries him back to the truck. Soon after departing, they come to a road block where a group of armed men try to force them to turn around. Tom takes the long way and continues south.
The Joads arrive at Weedpatch, a government camp, where Tom meets Timothy and Wilkie Wallace. They invite Tom to go with them to the farm where they work. The owner of the farm says that the Farmers’ Association is forcing him to lower wages, even though he knows the workers deserve more. He also cautions them that the Association, which thinks the camp is full of communists, might try to start trouble at the camp’s Saturday-night dance, allowing deputies to come in and throw the migrants out. Back at camp, a religious woman stops by the Joads’ tent and warns Rose of Sharon that camp activities such as plays and dances are sinful, and taking part in them has made women lose their babies. The men return from an unsuccessful job hunt. Ma and Pa miss home, and Ma begins to feel the weight of the people they have lost so far.
Saturday morning, the camp prepares for the dance. The Central Committee meets to discuss the possibility of the dance coming under attack; they decide to post men around the fences and on the dance floor. Ma assures Rose of Sharon, nervous after the earlier warning about sinful activity, that she will not have to dance with anyone. Stationed at the main gate, Tom spots some suspicious men who end up trying to start a fight. After being escorted off the floor, the troublemakers admit that they were paid to cause problems.
The Joads leave the Weedpatch camp following a month in which no one has been able to find long-term work. When the Joads stop to fix a flat tire, a man comes by and tells them of work picking peaches thirty-five miles away. Arriving at Hooper Ranch, they pass an angry mob of people near the gates. They are assigned a small cabin and begin work that afternoon. Making only five cents per box of peaches, the family must spend their day’s earnings on dinner. Tom investigates the mob from earlier in the day, sneaking past the guards around the perimeter. He finds Casy there leading a strike against the owner, who only wants to pay two-and-a-half cents per box, a rate that even the strike-breakers could soon face, and which could create further hardship for the Joads. As Tom and Casy talk, two men approach. One of them calls Casy a communist and takes a pick handle to Casy’s head, killing him. Tom grabs the pick handle and clubs Casy’s killer. In the struggle, Tom takes a blow to the head, ending up with a broken nose. He escapes and returns to the family. The Joads leave the ranch at dusk, with Tom hiding between the mattresses in the back of the truck. On the road, they come across a cotton plantation in need of workers; there are abandoned boxcars nearby where the cotton pickers live. Tom suggests that he should hide out in a culvert until his face heals. The rest of the family will pick cotton and live in a boxcar, sneaking over to bring Tom food.
Each boxcar holds two families; the Joads share theirs with the Wainwrights. Before long, the Joads can afford food and new clothing. When another girl bullies her, Ruthie reveals Tom’s secret. Ma, concerned that suspicion will fall on the family, tells Tom of Ruthie’s mistake. Tom decides to go off on his own and follow in Casy’s footsteps, fighting for people’s rights. Walking back, Ma runs into a farm owner in need of cotton pickers. At the boxcar, she tells the family about the work. Al has news of his own: he and Aggie Wainwright plan to get married. The next morning, as the family gets ready to pick cotton, Rose of Sharon insists that she wants to work, too. Against her better judgment, Ma allows Rose of Sharon to come along. When a storm arrives, Rose of Sharon catches a chill and becomes sick.
Pa notices that the water is rising and will eventually flood the boxcar. Rose of Sharon, still sick, goes into early labor. The rain causes more problems: cars flood and a tree uproots, destroying a dam that the men had just built for protection. Rose of Sharon delivers a stillborn baby, and is exhausted from the labor. Uncle John goes out to bury the baby, but instead he sets the makeshift casket adrift downstream. In the morning, the family—minus Al, who stays behind with Aggie—sets out to find a dry place. They see a barn and go inside where they find a boy and his father. The father is starving to death, having given all of his food to his son. The boy had gotten him some bread, but his father couldn’t keep it down; he needs something liquid to survive. Rose of Sharon and Ma exchange glances, and Rose of Sharon asks to be alone with the stranger. She offers her breast to the frightened man. After a slight protest, he drinks as Rose of Sharon runs her fingers through his hair.