Explain how Puritanism shaped the literary imagination in nineteenth-century America

In connection with this question, Nathaniel Hawthorne is the author who, for most readers, would first come to mind. Hawthorne was haunted by the stark images of early colonial New England, where his ancestors established a kind of theocracy of Calvinist Christianity in defiance of the Established Church (the Church of England) and the Stuart monarchy.
Hawthorne's attitude about Puritanism is ambivalent. He presents characters like Hester Prynne in The Scarlet Letter who defy the system and demonstrate their individuality and heroism. In other stories such as "The Maypole of Merry Mount" those who revel in "sin" don't show the same depth of character of Hester but are similarly punished by the religious authorities.
Yet in some instances Hawthorne admires the individualism shown by the Puritans themselves, as in the tale "Endicott and the Red Cross." This story is replete with irony in depicting the defiant gesture of Endicott in tearing the flag of the Red Cross, the symbol of the English monarchy. To Hawthorne, Endicott's act is a precursor of the American Revolution that was to take place one hundred and thirty years after Endicott. But the subtext of the story is the danger of extremism of any kind. Hawthorne does not spare the reader a description of the Puritans' ruthlessness in their punishment of religious "offenders" and in their attitude towards the indigenous Americans. The themes of other stories such as "Young Goodman Brown" and "Ethan Brand" involve the meaning of sin and evil, and express a tension between the reality of evil and the unfairness of judging the "sinner" who falls short of the impossible standards set by religion.
The themes of alienation in the work of Hawthorne's close friend Herman Melville, while not drawing directly on the Puritan background, are nonetheless similarly rooted in the obsessive religious attitudes of early America. The obvious example is Ahab's obsessive quest in Moby Dick. Bartleby depicts the gradual withdrawal from modern life and its imperfection by the title character. In Billy Budd we see a stark allegory of good versus evil.
Hawthorne, Melville and other Americans including Edgar Allan Poe show us, even in their basically secular orientation, an awareness of the importance of the powerful religious background of early America. Their approach, incorporating mysticism and fantasy, is a contrast to the greater realism of their English contemporaries Dickens, Thackeray, and the Bronte sisters, though the latter also show the power of the religious background of their culture in a different way.