Griffith did not use Dorothy in any of his earliest epics, but while he spent months working on "The Birth of a Nation" and "Intolerance", Dorothy was featured in many feature-length films made under the banner of Triangle and Mutual releases. They were directed by young Griffith protégés such as Donald Crisp, James Kirkwood, and Christy Cabanne. Elmer Clifton directed a series of seven Paramount-Artcraft comedies with Dorothy that were so successful and popular that the tremendous revenue they raked in helped to pay the cost of Griffith’s expensive epics. These films were wildly popular with the public and the critics. She specialised in pantomime and light comedy, while her sister appeared in tragic roles. Dorothy became famous in this long series of Griffith-supervised films for the Triangle-Fine Arts and Paramount companies from 1918 through 1920, comedies that put her in the front ranks of film comedians. Almost all of these films are now considered to be lost films.