Lewis based the town of Gopher Prairie on his own childhood hometown of Sauk Centre, Minnesota. Furthermore, the characters of the novel resemble the people he knew as a child. Lewis admitted that he based the character of Carol Kennicott on himself. In a biography of Lewis, the literary critic Mark Schorer wrote that Lewis shared his heroine's search for individual happiness: "Carol is [Sinclair Lewis], always groping for something she isn't capable of obtaining, always dissatisfied, always restlessly straining to see what lies just over the horizon, intolerant of her surroundings yet lacking any clear vision of what she wants to do or be."

Lewis also expresses his own liberal opinions about contemporary social issues—such as his support of the women's movement and the labor movement—through the characters of Carol and Bjornstam. Lewis records his own love-hate relationship to his hometown through Carol: as a child he desperately longed to escape Sauk Centre, but when he left to attend college and make a career for himself, he realized that he could never mentally escape his hometown, as part of it would always remain with him. Carol achieves this same realization when she moves to Washington, D.C. Furthermore, just as Carol resembles Lewis himself, Dr. Will Kennicott is modeled on Lewis's father, Dr. E.J. Lewis. Lewis's detailed descriptions of the duties of the medical profession were possible only because of his familiarity with his father's work; indeed, he frequently accompanied his father on house calls and once witnessed his father perform an amputation. Lewis claimed that he based the episode of Kennicott amputating a farmer's arm on a real-life experience.

Lewis was largely a novelist with a mission: as a social critic, he sought to portray the defects of small town America—its rigid conformity, narrow- mindedness, hypocrisy, materialism, and lack of interest in current social or intellectual issues. Wanting his reading public take a close look at themselves and their society, Lewis used satire and ridicule to mock contemporary society. Furthermore, to do so effectively he wanted to depict small town life realistically. In Chapter 22, he notes that only two traditions existed in American literature at the time to portray small town life, both of which exaggerated greatly and therefore failed to depict small town life realistically. One tradition portrayed small towns romantically, as places of natural beauty and friendly faces. The other tradition dismissively portrayed backwater small towns as the hometowns of "hicks." Lewis broke from literary tradition by portraying Gopher Prairie as a realistic and unromantic small town. Throughout the novel, he emphasizes the fact that Gopher Prairie—and every American small town—represents a microcosm of the entire country. The characters, prejudices, and problems found in Gopher Prairie can be found everywhere. Furthermore, Lewis makes minute observations of everyday life in order to realistically depict what life is like at the specific time and place with which he is concerned. The characters speak in everyday dialogue, and the immigrants speak with accents. Moreover, Lewis anchors the novel in the atmosphere of early twentieth century America by referring to contemporary social issues, such as the women's suffrage movement and the labor movement.

Cultured and well read, Carol has spent time in the city and finds small town life ugly and stifling. The struggle between her desire to make Gopher Prairie a better place and Gopher Prairie's resistance to her reform effort represents the novel's major conflict. Will, on the other hand, has always lived in Gopher Prairie (except for the years when he attended medical school in Minneapolis) and finds the townspeople warm and friendly. In many ways, the conservative Kennicott represents Gopher Prairie as a whole because he, like the town, steadfastly resists change. He considers the liberal-minded Carol "highbrow" because she prefers the theater to cowboy movies and makes his unsophisticated friends uneasy whenever they visit. As Carol admits, she regards people like Will as "stupid" while he regards people like Carol as "neurotic." Throughout the novel, Carol remains an incurable romantic, while Will remains materialistic, unimaginative, and practical. The end scene with the two characters talking encapsulates much of the contrast between their personalities. While the dreamy Carol imagines future social reforms, the practical Kennicott thinks about the weather and storm windows. Though we may empathize with carol, her romantic nature may also strike us as immature and self-deceiving, as she never achieves what she desires because she is impractical and self-conscious of criticism. Will, on the other hand, remains a stable, mature, and confident—though static and unexciting—figure.