Librivox: Main Street by Lewis, Sinclair

Summary: Carol Milford is a liberal, free-spirited young woman, reared in the metropolis of Minneapolis. She marries Will Kennicott, a doctor, who is a small-town boy at heart. When they marry, Will convinces her to live in his home-town of Gopher Prairie, Minnesota. Carol is appalled at the backwardness of Gopher Prairie. But her disdain for the town's physical ugliness and smug conservatism compels her to reform it. (Summary from Wikipedia).