 The film followed McCay 's earlier successes in animation : Little Nemo ( 1911 ) , How a Mosquito Operates ( 1912 ) , and Gertie the Dinosaur ( 1914 ) . McCay drew these earlier films on rice paper , onto which backgrounds had to be laboriously traced ; The Sinking of the Lusitania was the first film McCay made using the new , more efficient cel technology . McCay and his assistants spent twenty @-@ two months making the film . His subsequent animation output suffered setbacks , as the film was not as commercially successful as his earlier efforts , and Hearst put increased pressure on McCay to devote his time to editorial drawings . 
