What is the main conflict in Sister Carrie by Theodore Dreiser?

Harpers refused the first copy, and the book went to Frank Doubleday. After the Doubleday printers typeset the book one of the partners' wives read it and so strongly opposed its sexual nature that the publisher produced only a few editions.

In addition to the book's theme of sexual impropriety, the public disliked the fact that Theodore Dreiser presented a side of life that proper Americans did not care to acknowledge. Even worse, Dreiser made no moral judgements on his characters' actions. He wrote about infidelity and prostitution as natural occurrences in the course of human relationships. Dreiser wrote about his characters with pity, compassion, and a sense of awe.