It is Sunday afternoon in late March of 1935 in Waxahachie, Texas, a small town some 40 miles south of Dallas. During the opening credits, a popular Protestant church hymn "Blessed Assurance" is playing, giving the audience glimpses of the central Texas prairie, people leaving church, having lunch in a restaurant, Sunday dinner at home, a homeless black man going up to a door for a meal, a homeless woman living in her car, and abject poverty nearly all blacks were forced to live in due to the segregation and discrimination laws. The hymn ends with Royce Spaulding, the town sheriff, saying grace for he and his family. During the lunch meal prayer, there are gun shots being fired outside. Sheriff Spaulding is summoned by a deputy that a drunken young negro Wylie is firing shots. The young man accidentally fires his gun shooting the sheriff in the chest and killing him instantly. Soon after his body is brought into the home, local vigilantes have dragged the body of Wylie to his death and displaying to Edna Spaulding outside her home reminding her that negro's killing whites will never go unpunished, even if accidental. Her sister Margaret arrives and tells them to leave.
Meanwhile, an affair has been going on between Edna Spaulding's brother in law, Wayne Lomax, and teacher Viola Kelsey at an abandoned shack on the prairie. Edna and her sister, Margaret Lomax are preparing the body of her husband for the funeral and have the wake at Edna's house with numerous people attending and bringing potluck food. Margaret tries to comfort Edna with Edna unsure about what she will do to support the family because she has never worked outside the home and knew nothing about her husband's finances.
At dusk, the hanged body of Wylie has been recovered by family members and the next day we are shown the very simple, bluesy funeral of Wylie's burial in a pine box in a segregated negro cemetery of homemade wood markers, whereas the funeral of Edna's husband is very elaborate in comparison and nicely done at a church and cemetery. Soon after the funeral and after the last mourners leave the house, a homeless black man named Moze comes to Edna's home if she has any work for him. Edna tells her she can fix him a plate of food, but then needs to leave.
The next morning, Edna hears wood being chopped outside in her yard. Moze is still around. She tells him once again she can make him a plate of food, but then needs to leave. Moze tells her about all kinds of handyman projects that can be done around the house and while doing so, he sneaks a set of silverware to steal.
Local banker Albert Denby makes a trip to Edna's home and tells her the situation of the debt on the home and that she may need to sell her home and move in with relatives in order to make ends meet. Edna refuses and is determined to keep her homestead and children and find a way to make ends meet.
That night, a local sheriff brings Moze to Edna's home having caught him with the stolen silverware and Moze claiming to work for her. Edna defends Moze to the sheriff telling him he didn't go with the silverware where he was supposed to. Edna now sees an opportunity to hire Moze inquiring him how much he knows about cotton farming, but also assures him she will shoot him herself if he ever tries to steal from her again.
Edna makes a trip to the downtown bank and asks Mr. Denby if he can teach her how to write a check and she also tells him she has hired a negro man to help out that is giving her tips on how to make money cotton farming. Mr. Denby dismisses her idea as very wrong and ignorant hiring a negro and that many white property owners have sold their homes or been foreclosed on. Edna stands her ground that she is moving forward.
On April 5, Edna and Moze are at Mr. Simmons' Cotton Gin to purchase seed for a cotton crop. Moze spots right away she's being sold a lower grade seed for higher grade price and Edna tells Mr. Simmons it's the wrong seed. Mr. Simmons berates and intimidates Moze for his "honest mistake" and gives Edna the higher quality seed.
Moze is back at Edna's place nailing good luck charms on the barn he is sleeping in. He's mumbling to himself about how he could have been killed for speaking up. Edna's son Frank introduces himself to Moze while he's working. Moze refuses to warm up to the boy at first, but Frank is more than happy to help him work and assist him.
Mr. Denby makes a trip back to Edna's home introducing his brother Will, a blind World War 1 veteran that he offers to live with her and pay her room and board per month. Despite Mr. Denby trying to butter Will up and Edna trying to be friendly and make small talk with Will, he is reluctant and tersely tells Edna he just wants his space and not to be felt sorry for.
There is a dance going on at an old white wood frame house with a group called The Lone Star Syrup Boys playing and many townspeople attending. Wayne gets home from work and he and Margaret make love. They arrive late at the dance with Buddy and Viola Kelsey having been concerned about them. Viola is now upset and keeps a distance from Wayne because she knows he still loves his wife and has sex with her.
Back at the Spaulding place, Frank and Possum sneak into Mr. Will's bedroom and play the story "Trent's Last Case" on his victrola. Edna calls the kids almost immediately and in a state of panic, Frank runs the needle across the record scratching it, putting it back in its case, and coming downstairs.
Some moments later, Edna is preparing herself a hot bath in a galvanized steel tub and Mr. Will storms into her room angrily not realizing she's naked and bathing yelling at her feeling humiliated, that he would love to leave her house if there were other choices, and is furious about her children going through his things. She stands up for her kids, he hits the water in the tub and is now embarrassed. He exits the room.
At dawn, Edna and Moze begin plowing the 30 acres of land to begin the cotton crop. There is also a brief scene of the Lone Star Syrup Boys tired and on the road.
Viola is outside at the schoolhouse during recess and Wayne drives by staring and flirting with her. She's distressed at this and goes to the back of the schoolhouse about to light an Old Gold cigarette. Several boys, including Frank Spaulding, are behind the school sneaking a cigarette and get caught.
Viola brings Frank home from school and very reluctantly Edna decides to administer punishment. Frank tells her that he would have received "ten good licks" from his father. She follows through with it in the pantry and Frank manages to save face during the punishment. Edna is very upset by having done it and confesses it to Mr. Will.
Margaret is at her home beauty shop tending to a customer and it's getting darker, radio static, and lights flickering despite being the afternoon. At the same time, Moze is working in the fields and sees a tornado coming through. Viola leads her school to the back of the classroom using a piano as a shield. Frank runs to his home. The woman living in her car tries to get Frank to come to safety in the vehicle, but he refuses. At Margaret's home, a customer shuts a window with it shattering and small shards of glass hitting her in the face. Moze gets the family to safety in the cellar and Frank makes it in time. Part of the schoolhouse is torn off and many other homes are totally destroyed.
After the tornado is over, there is only minor damage of the Spaulding place that can be fixed in days, but the schoolhouse is badly damaged and the woman in her car was killed with the car turned upside down. Viola's husband Buddy comes to the rescue. After seeing the damage she pleads with him to leave town for the city because of the poverty and frequency of tornados.
It is now September and Edna is in the kitchen preparing breakfast and Mr. Will turns on the radio with the farm and livestock report. It is announced that cotton is now at an all time low of 3.5 cents a pound.
Back at the bank, Edna is pleading to Mr. Denby if somehow the payment of the house can be deferred, as she owes over $150, but only has $24 in her account. Mr. Denby goes to ask his boss, the president of the bank, if it can be done. In the background he shakes his head no. Edna looks at a series of photographs of people bringing in the first bale of cotton a year receiving an additional $100. Edna sees this as an opportunity to be able to make the payment, hire some workers, and still have some money leftover.
The cotton is ready to be picked. Moze totally dismisses Edna's proposal to get the cotton picked as quick as possible and get the first bale in. He warns her that the toil from picking the cotton and cuts on her hands will be unbearable. Edna does not back down and tells Moze if they don't do it that he will be back to begging for meals, Mr. Will will be forced to live in a state home, and she and her kids will be separated and lose the homestead.
The Lomax and Kelsey couples are at the Lomax home playing cards. Buddy Kelsey announces to them he and Violet are moving to Houston. There is some considerable tension between Wayne and Viola throughout the night. Wayne makes a pass at Viola attempting to grab a set of cards out of her hand and she pulls away. Margaret spots this and knows something is not right. Buddy and Viola leave and Margaret slaps Wayne in the face knowing he's been sleeping with Viola and tells him she doesn't love him and wants a divorce.
Edna, Moze, Frank, and Possum are all picking cotton in the hot sun for hours with Edna getting cuts on her fingers from the hulls. Moze is annoyed by all this thinking it won't work. After having finished four acres, Edna inquires with Moze about hiring pickers. Ten is what they should have. She leaves it to Moze to hire them and risk losing money if she doesn't get the first bale in.
The next morning, ten men, women, and children are at the door hired to pick cotton. Edna feeds them a breakfast of cornbread and tea. Afterwards, they go to work. Mr. Will hears several truckloads of people passing through and announces to Moze someone else trying to get ahead of getting the first bale in. Moze tells the workers they need to go faster and have only 3 days left. Edna is struggling to retain her strength and dignity.
A country instrumental version of La Golindrina is playing with Edna and her husband dancing. She wakes up from a dream and it is early morning with Mr. Will in the kitchen picking string beans. Edna is stiff, exhausted, and telling him of her dream while still half asleep. She realizes there is only one day left to pick cotton.
It is night and oil lanterns have been set up so they can pick cotton. Wayne and Margaret have joined in to speed it up. Mr. Will is on one of the cotton wagons listening to Trent's Last Case on his victrola outside while they finish.
A beyond-exhausted Edna is crawling through the cotton fields searching for more cotton to pick with Moze giving her the good news they have now finished.
Edna and Moze are parked at Mr. Simmons' cotton gin awaiting his arrival. Moze is giving her instructions on how to bargain with him. Mr. Simmons arrives and tells Edna he needs to charge a fee to gin the cotton, which Moze told her otherwise not to accept. She requests for 4.5 cents a pound, despite the 3.5 cents that was recent on market prices. Mr. Simmons gets tough and insists he will give her 2.75, she drops it to 4. He finally bargains with 3.5 and says there is no way he can go higher. He asks her to leave and take her business elsewhere. She looks at the picture on his desk, which was one of the pictures in the bank earlier and reminds Mr. Simmons that this will probably be the first year he does not get the first bale of cotton for the season and that another dealer might just go for the same price she requested. He tersely asks her to sit down.
Edna comes out of Mr. Simmons' office. She managed to get the cotton up to 3.75 cents a pound and a received nice check for it. She's still somewhat dissatisfied and believes they could have done more, but Moze insists they would have died from overwork.
Edna is sitting in her kitchen now repairing a set of work shoes and somewhat at peace and Mr. Will approaches her asking for a cup of tea. He reluctantly asks her a question as to what she looks like. She goes over the details of her personal appearance with him comparing herself to other relatives. Then the teapot whistles and his tea is ready.
Edna, her children, and Wayne and Margaret Lomax go to a town dance at an outdoor shed. The Lonestar Syrup Boys are performing once again playing La Golindrina. Frank asks his mother Edna to dance with him. There are still tensions between Wayne and Margaret, they dance together, and he's still trying to make up with her. Buddy and Viola Kelsey are also at the dance with a still jealous Viola watching Wayne and Margaret dance.
Back at the Spaulding farm, Mr. Will is caning a chair and hanging out with Moze with Moze discussing the success of Edna's bargaining with the cotton buyer. He hears some activity going on in the back, but Moze dismisses it. But he goes outside to check on what's going on. There are four Ku Klux Klansmen that go after Moze beating him. Mr. Will steps outside with Sheriff Spaulding's gun threatening the klansmen to leave. He identifies the men as customers of his he knows and Mr. Simmons, the cotton buyer, who is obviously outraged at having been cheated out of money by Edna because of Moze's instructions to her on how to bargain with him and taking it out on Moze. Mr. Will shoots the gun, the men leave, and Mr. Simmons assures Moze he is not yet finished with him.
Edna is back home rushing to Moze at what has happened. He's in the barn having cleaned it and packed his belongings. He has cuts and bruises on his face from the beatings. He tells her he needs to leave before the klansmen come back. She worries that he'll be killed and won't be able to manage without him. But Moze knows he needs to leave. He gives Edna small gifts he wants she and her children to have. She is saddened at his leaving, but reassures him that he was the one that made it happen by tilling her land, planting the cotton, and bringing in the first cotton crop in the county for the year and his race had nothing to do with it. Moze accepts her compliment and leaves.
Back at the church, the choir is once again singing "Blessed Assurance". Bud and Viola Kelsey are now leaving town passing by the church. The pastor gives a brief sermon about love to the small congregation. Margaret takes Wayne by the hand assuring him of forgiveness. During communion, the choir sings "In the Garden". During this scene, the elements of bread and wine are passed from person to person in a now large congregation dressed casually and in their Sunday Best telling each other "Peace of God". Included in this are The Lonestar Syrup Boys, the woman killed in her car during the tornado, Mr. Denby, Moze, and finally Sheriff Spaulding saying "Peace of God" to Wylie, the young negro boy that accidentally killed him. It is a symbolic scene indicating the "New Heaven and Earth" in the Bible that poverty, racism, oppression, and hatred is all gone and that love and forgiveness are now the rule.