Larry is an academic and aspiring writer originally from Albuquerque, New Mexico. After his parents die in an aviation accident, he pursues English literature and secures a temporary teaching position at a university in Madison, Wisconsin, during the Great Depression. He is highly ambitious and works constantly, often isolating himself in his basement apartment next to the furnace to write his first novel. He struggles with feelings of inferiority when interacting with his wealthier, East Coast colleagues.

Sally is an academic trained in Classics and the devoted wife of Larry Morgan. Coming from a modest background, she supports her husband through his early career anxieties in Madison with unquestioning loyalty. She contracts polio, which leaves her reliant on crutches and profoundly alters her physical capabilities and daily life. Despite her disability, she maintains a strong sense of reality and refuses to indulge in self-pity.

Charity is an imposing, wealthy New Englander who highly values social capital and traditional rituals. She actively directs the lives of those around her, structuring days and careers according to her specific standards. In the present-day framing of the novel, she is suffering from a terminal illness but insists on maintaining her family's rituals. Despite her imperious nature, she demonstrates fierce loyalty and material generosity toward her friends during their medical crises.

Sidney is an English professor from a wealthy Pittsburgh family, educated at Yale and Harvard. Despite his academic pedigree and material comfort, he harbors secret ambitions to be a poet rather than a conventional scholar. He struggles with deep insecurity and frequently defers to his wife's strong expectations regarding his career, leading to quiet resentment and emotional stagnation.

Hallie is the daughter of Sidney and Charity Lang. She grows up alongside the Morgan family and visits them during the novel's present-day sequences. She remains largely unaware of the deep sacrifices her parents made for the Morgans in the past until Sally explains them.

Moe is Hallie's husband and the son-in-law of Sidney and Charity Lang. He accompanies Hallie to visit the Morgan family and assists the aging couples during their present-day reunion.

Lang is the firstborn daughter of Larry and Sally Morgan. She survives a dangerous breech birth during the early years of her parents' time in Madison, arriving with a broken arm.

Aunt Emily is a prominent member of Charity's affluent family at Battell Pond. She reads Henry Wadsworth Longfellow's poetry to children, an act that deeply shapes Charity's childhood and her subsequent view of the world.

Alice is the wife of a colleague at the university in Madison. She shares a brief, impulsive kiss with Larry during a period when he is separated from Sally and feeling lonely.