McCay was an early animation pioneer; between 1911 and 1921 he self-financed and animated ten films, some of which survive only as fragments. The first three served in his vaudeville act; "Gertie the Dinosaur" was an interactive routine in which McCay appeared to give orders to a trained dinosaur. McCay and his assistants worked for twenty-two months on his most ambitious film, "The Sinking of the Lusitania" (1918), a patriotic recreation of the German torpedoing in 1915 of the "RMS Lusitania". "Lusitania" did not enjoy as much commercial success as the earlier films, and McCay's later movies attracted little attention. His animation, vaudeville, and comic strip work was gradually curtailed as newspaper magnate William Randolph Hearst, his employer since 1911, expected McCay to devote his energies to editorial illustrations.