The film followed McCay's earlier successes in animation: Little Nemo (1911), How a Mosquito Operates (1912), and Gertie the Dinosaur (1914).

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.

The film opens with a live-action prologue in which McCay busies himself studying a picture of the Lusitania as a model for his film-in-progress.

[2] Intertitles boast of McCay as "the originator and inventor of Animated Cartoons", and of the 25,000 drawings needed to complete the film.

After some time, the SM U-20 slices through the waters and fires a torpedo at the Lusitania, which billows smoke that builds until it envelops the screen.

[4] A second blast rocks the Lusitania, which sinks slowly into the deep as more passengers fall off its edges,[4] and the ship submerges amid scenes of drowning bodies.

[14] Inspired by the flip books his son brought home,[15] McCay said he "came to see the possibility of making moving pictures" of his cartoons.

[27] McCay said that he gathered background details on the Lusitania from Hearst's Berlin correspondent August F. Beach, who was in London at the time of the disaster and was the first reporter at the scene.

[29] McCay had assistance from his neighbor, artist John Fitzsimmons, and from Cincinnati cartoonist William Apthorp "Ap" Adams,[1] who took care of layering the cels in proper sequence for shooting.

[30] McCay provided illustrations during the day for the newspapers of William Randolph Hearst, and spent his off hours at home drawing the cels for the film, which he took to Vitagraph Studios to be photographed.

[34] The cels used were thicker than those that later became industry standard, and had a "tooth", or rough surface, that could hold pencil, wash, and crayon, as well as ink lines.

The amount of rendering caused the cels to buckle, which made it difficult to keep them aligned for photographing; Fitzsimmons addressed this problem using a modified loose-leaf binder.

[36] The Sinking of the Lusitania was registered for copyright on July 19, 1918,[3][c] and was released by Jewel Productions[28] who were reported to have acquired it for the highest price paid for a one-reel film up to that time.

[36] The animation combines editorial cartooning techniques with live-action-like sequences,[27] and is considered McCay's most realistic effort; the intertitles emphasized that the film was a "historical record" of the event.

[39] McCay made stylistic choices to add emotion to the "historical record", as in the anxiety-inducing shots of the submarines lurking beneath the surface, and abstract styling of the white sheets of sky and sea, vast voids which engorge themselves on the drowning bodies.

[41] Animation historian Paul Wells suggested the negative space in the frames filled viewers with anxiety through psychological projection or introjection, Freudian ideas that had begun circulating in the years before the film's release.

[46] In the era that followed, animation studios made occasional non-fiction films, but most were comedic shorts lasting no more than seven minutes.