The Gentleman from Indiana presents Tarkington's home state and its inhabitants in a highly idealized fashion. It is a romance, but a romance with realistic touches. It records authentically the speech patterns and lifestyles of Indianians of the 1870s and 1880s. The corruption of local politics is also accurately described. During his single term as a member of the Indiana General Assembly (January to March 1903), Tarkington learned how widespread corruption was in public life. He made his experiences in politics the background for a series of short stories, In the Arena (1905).

As The Gentleman from Indiana concludes, the author shows that rural Indiana is changing. Oil companies are establishing themselves in the area.

They threaten to bring new classes of people and new problems.