Romanticism was an international philosophical and artistic movement that emerged in the late 18th century. It valued emotion, nature, and the individual spirit over reason and social conformity. American Romanticism shared many traits with British Romanticism but differed in its emphasis on the common man as hero and on nature as a source of spirituality. Major American Romantic authors included Emerson, Thoreau, Poe, Hawthorne, Melville, Dickinson, and Whitman. Their works explored themes of the frontier, immigration, industrialization, and a search for new spiritual roots.