One of Ours (1922) earned Cather the Pulitzer Prize in 1923.
The book follows the journey of Claude Wheeler, from his home a farm in Nebraska to the bloody battle fields of France and World War I. In the first part of the book, Claude has his horizons expanded when he attends a university and meets the Eldrich family. They have broader views and live a more lively life than Claude has known. He quickly adapts their ways, but is called away from the university and back to his family farm where his father has just expanded their operations and needs his help.
Stuck back on the farm, Claude marries a local woman, Enid Royce, but the marriage is an unhappy one for Claude; his wife seems much more interested in activism than fulfilling the idealistic role that Claude had envisioned. Drifting, and looking for purpose Claude answers the call to battle.