The document discusses the literary movement of Naturalism in American literature from the 1890s to the 1920s. Naturalist authors such as Jack London, Edith Wharton, and Frank Norris presented reality without illusion or embellishment. Their works explored how individuals and environments interacted as well as themes of survival, determinism, and violence. The document also provides brief overviews of other literary periods and movements such as Modernism in the early 20th century, Realism from 1865-1900 led by authors like Mark Twain and William Dean Howells, and the Harlem Renaissance of the 1920s-1930s which gave voice to African American authors.