Carol Milford, the daughter of a judge, grew up in Mankato, Minnesota, and became an orphan in her teenage years. In college, she reads a book on village improvement in a sociology class and begins to dream of redesigning villages and towns. After college, she attends a library school in Chicago and is exposed to many radical ideas and lifestyles. She becomes a librarian in Saint Paul, Minnesota, the state capital, but finds the work unrewarding. She marries Will Kennicott, a doctor, who is a small-town boy at heart.
When they marry, Will convinces her to live in his hometown of Gopher Prairie. Carol, filled with disdain for the town's physical ugliness and smug conservatism, immediately formulates plans to remake Gopher Prairie.
She speaks with its members about progressive changes, joins women's clubs such as the Thanatopsis, distributes literature, and holds a party to liven up Gopher Prairie's inhabitants. Despite her efforts, these ventures are ineffective and she is constantly derided by the leading cliques.
She finds some comfort and companionship with a variety of social outsiders in the town, but these companions all fail to live up to her expectations.
After a political meeting of the Nonpartisan League is broken up by local authorities, Carol leaves her husband and moves for a time to Washington, D.C., to become a clerk in a wartime government agency. She eventually returns. Nevertheless, Carol does not feel defeated:
I do not admit that Main Street is as beautiful as it should be! I do not admit that Gopher Prairie is greater or more generous than Europe! I do not admit that dish-washing is enough to satisfy all women! I may not have fought the good fight, but I have kept the faith. (Chapter 39)
