A lenticular 3-D poster was produced for Uncle Sam. Reportedly, only 10 of the 3-D posters were issued. The images shows four versions of Uncle Sam changing from an old man into a ghoul.
The ending is a reference to the ending of Lucio Fulci's City of the Living Dead (1980). The Lucio Fulci dedication before the end credits confirms this.
Barry, who is supposed to be blind, takes the food given to him by his parents at the Fourth of July rally without any verbal prompt, as if he can see it.