American novelist Theodore Dreiser popularized naturalism in the United States during the early 1900s. Although the movement was begun by French writer Émile Zola, it was largely through the perseverance of Dreiser that it became a force in America. Emphasizing realism and accuracy in art, naturalism went beyond these qualities to reveal how humans are shaped by their circumstances and environment. Renowned literary critic Irving Howe described Dreiser as, "one of the very few American giants we have had."