How did the rise of cities and mass culture affect writers such as Flannery O'Connor?

Flannery O'Connor is known for her themes that integrates the transition of traditional values and contemporary values. The rise of cities allows her to portray her works effectively and make a comparison on them. In one of her works, "Everything that rises Emerge", it tells of a college graduate son that knows better of the world and his mother who is uncomfortable on anything new in the city.