"Realism" and "naturalism", its literary development (or for some its regression), have proved difficult for critics to define and come up with a single, unifying definition. Writers as diverse as William Dean Howells, Henry James, Stephen Crane, Theodore Dreiser, Sarah Orne Jewett, kate Chopin and Mark Twain have been included under these labels. One of the ways to approach realism is certainly to see it as a contrast to the literary ideals of Romanticism (in America also referred to as Transcendetalism). These ideals stressed the importance of personal invention, irrationality, passion and feeling both as themes and form of literary composition. The reaction against such ideals is sometimes seen as prompted by the horrors of the civil war. Some see a clear connection between the war and the Romantic stress on irrationality and personal feelings. In the Enotes guide to American Realism, for example, this point is made clearly:
After the Civil War, American authors and scholars turned against the irrationality and vanity of contemporary literature. According to Benardete, some even blamed the conventions of romanticism—idealism, chivalry, heroism, absolute moral stances—for fostering a national vision which inevitably led to war, causing Americans “to fight when they might have negotiated, to seek empty glory though it cost them their lives.”
Although realists like James paradoxically stated that to create realist characters one should rely on the large powers of human imagination, a large part of realist writers was fascinated by technological progress and by scientific thinking, which they saw as antidotes against the irrational divisions of the war.
Realism also tried to foster unity by adopting a reporting mode, by claiming to be a transparent window on reality, although, of course, we should be wary of taking this ambition at face value. It tried to explain new social phenomena that had partly been engineered by the victory of Northern economic values after the civil war and whose consequences might further divide and disorient American society, for example, the shift from an agrarian to an industrial economy, the mass migration towards cities both from the countryside and other countries. Realism was not, however, an exclusively urban literary movement. American realist writers of the so-called "local color" type also carried out an important unifying function, detailing to the new nation the customs and traditions of its different regions, thus contributing to foster a sense of shared national identity after the war.