A peaceful Quaker family's sanctity is tested during the Civil War.

The Birdwells, a prosperous Pennsylvania Quaker family, try to remain detached from the Civil War that is raging to the south. As the family prepares to go to Sunday meeting, daughter Mattie primps and fantasizes about her sweetheart, Gard Jordan, while older brother Josh plays war with younger brother Little Jess, but warns that their preacher mother Eliza does not like war talk. While father Jess hitches his horse Red Rover to a surrey, he laments to black farm hand Enoch that the horse is not as fast as he appears. On the way to town, Gard's father, neighboring farmer Sam Jordan, rides up alongside the Birdwells, initiating their Sunday racing ritual. Eliza strongly disapproves of racing but is unsuccessful in convincing the amiable Jess to stop. After Sam's horse once again wins, the Birdwells go to their meetinghouse, while Sam and Grad attend Methodist services. A few minutes later, Maj. Harvey of the Union Army enters the meetinghouse to urge the Quaker men to take up arms against the South. Although some men, including Jess and Josh, admit doubts about their pacifist beliefs, Harvey is unable to change anyone's mind. A few days later, Gard, who is an army officer, comes to call on Mattie and ask the family if they plan to go to the county fair. When the excited children lament that Eliza's strictness will prevent their attending, Jess intercedes. At the fair, while Eliza visits a quilting booth, Little Jess enjoys the sideshows, Josh and his friend Caleb watch a wrestling match, Jess and Sam peruse Quigley's organ emporium and Gard convinces Mattie to dance with him on the pavilion. When Eliza sees Mattie dancing, she is shocked and orders her daughter home, despite Gard's plea that he wants to spend his last day of leave with Mattie. Meanwhile, Caleb enters a wrestling match but suddenly quits because he thinks he has hurt the other wrestler. A few men who had bet on Caleb start to intimidate and hit him and Josh, who refuse to hit back. The incident is stopped by Jess, who grabs the most abusive man and pushes him into a rain barrel, in full view of the disapproving Eliza. Soon Jess, who sells nursery stock, leaves on a business trip through Pennsylvania and Ohio. Josh has never accompanied his father before and looks forward to the adventure, despite Eliza's concerns for their safety. On the last day of their trip, Jess stops at the farm of the Widow Hudspeth, whose three man-hungry daughters are delighted to have the bashful Josh and Jess spend the night. While riding with the widow, Jess is impressed by her ugly mare "Lady," who refuses to let other horses pass her. Because the widow does not want her daughters' potential suitors to be upstaged by Lady, she trades Lady for Red Rover. When Jess and Josh return home, Eliza is delighted that Josh has traded Red Rover for a "good, plain animal," but her happiness turns to anger when Quigley delivers an organ that Jess had purchased without her knowledge. Eliza stands in the doorway and forbids Jess to bring in the organ. Jess, who does not like the word "forbid," moves the organ inside, prompting Eliza to leave for the barn. That night, after the children have gone to bed, Jess goes into the barn and speeds the night there with Eliza. The next morning, as the pair lovingly walks arm-in-arm toward the house, Eliza makes Jess promise that the organ will stay in the attic and not be played on meeting day. On Sunday, Jess makes an excuse to take their smaller carriage to town and hitches up Lady. For the first time, he is able to best Sam in the race, much to Eliza and Sam's chagrin. That night, Gard, who has returned to organize the home guard after sustaining a battle wound, comes to see Mattie. As Mattie, Josh and Little Jess question Gard about his experiences, Josh says that he wants to join the home troops, but Gard asks him to think more about his decision. Later, as Gard and Mattie kiss, Josh and Enoch assist as the family cow gives birth, and Enoch worries when Josh wonders aloud what death would be like. A few days later, Gard comes to visit Mattie, who is at the river with Little Jess. She is angry when she realizes that Gard has overheard her talking aloud about his handsomeness and runs back to the house. Just then, Josh rides home and reports that Confederate soldiers are less than thirty miles away and will overrun their farm by tomorrow. Gard pleads with Jess and Eliza to take the children and hide in the woods, but Eliza says that if it is God's will, there is nothing they can do. Enoch then asks Gard for a gun, confessing that he is a runaway slave and would not have a chance with the Confederates. When Mattie, who is listening from her room, overhears Gard say that he is leaving to join the home guard, she runs after him. They confess their love for each other and promise to marry. The next morning, after talking with Jess, who understands how he feels, and Eliza, who has urged him to pray, Josh takes a shotgun and rides off on Lady to join the home guard. While Josh nervously takes position at the river, where the home guard will try to prevent the Confederates from crossing, Elder Purdy rides to the Birdwell farm and angrily relates that his farm has been looted and his crops burned. Although Jess offers to share what he has, Purdy, who previously had boasted that he would never betray his principles, lashes out at Jess for not taking up arms. His tirade is interrupted when Sam arrives and tells Purdy that he will fight for both himself and Jess and is glad that someone is holding out for a better way of settling differences. When the Confederates start to cross the river, the battle begins. Seeing the killing of a man who had been kind to him, Josh repeatedly loads his shotgun to fire at the approaching Confederates, as tears roll down his cheeks. A short time later, Lady arrives at the farm riderless, causing Eliza to break down, sure that her son is dead. When she sees Jess take his shotgun and ride out, she is hurt but does not try to stop him. Soon some Confederate soldiers arrive at the Birdwell farm, and Eliza surprises them by offering food and hospitality. However, when one of the soldiers grabs Eliza's beloved pet goose Samantha, she becomes hysterical and repeatedly hits the soldier with her broom. The soldier lets Samantha go and apologizes, then departs with the others, leaving an ashamed Eliza, who asks her children not to say anything to their father. Meanwhile, as Jess approaches the river, he encounters the mortally wounded Sam and reminisces about their races before his friend dies. Just then, a lone Confederate soldier takes a shot at Jess, who is only grazed, but pretends to be dead. Concluding that both men are dead, the soldier walks away to reload his rifle, but Jess stands up and struggles with him. Jess has a clear shot at the soldier but, grabbing his gun, tells him that he will not kill him and to walk away. A few minutes later, Jess comes upon the scene of devastation at the river. Among the dead bodies, he finds Josh, alive, but heartsick at having killed. Jess takes his son home, where Eliza welcomes them. Some time later, after the battles are over, Enoch hitches up the surrey for Jess, Josh, Eliza and Little Jess to ride to Sunday meeting as Gard and Mattie ride behind in their carriage.