 The Sinking of the Lusitania was noted as a work of war propaganda , and is often called the longest work of animation of its time . The film is likely the earliest animated documentary . McCay 's biographer , animator John Canemaker , called The Sinking of the Lusitania " a monumental work in the history of the animated film " . Admired by his animation contemporaries , Canemaker wrote that it " did not revolutionize the film cartoons of its time " as McCay 's skills were beyond what his contemporaries were able to follow . In the era that followed , animation studios made occasional non @-@ fiction films , but most were comedic shorts lasting no more than seven minutes . Animation continued in its role of supporting feature films rather than as the main attraction , and rarely received reviews . Lusitania was not a commercial success ; after a few years in theaters , Lusitania brought McCay about $ 80 @,@ 000 . McCay made at least seven further films , only three of which are known to have seen commercial release . 
