The genesis of Duck Soup, known under various working titles, such as "Cracked Ice" and "Grasshoppers," was influenced by two other projects that tangentially involved Marx Brothers alumni. Herman Mankiewicz, the producer on Duck Soup, had just supervised the shooting of another Paramount comedy, Million Dollar Legs (1932), starring W.C. Fields. Herman's younger brother Joe had written that film's original story about a fictional country, Klopstokia, beset by chaotic foreign intrigue, nutty spies, and internal political strife. Sound familiar? The cast even featured a young actress named Susan Fleming, playing the President's daughter, who was to become Harpo Marx's betrothed two years later. While there are no definite connections between the two projects, Herman Mankiewicz's involvement in both can not be easily dismissed.

The other influence on Duck Soup was a political play called Of Thee I Sing, by George S. Kaufman (who wrote two of the Marxes' stage plays) and Morrie Ryskind, which took satirical swipes at French and U.S. relations. The Marxes briefly flirted with the idea of adapting the play for the screen. Instead, they incorporated many of the same themes into early drafts of "Cracked Ice," soon to be renamed Duck Soup.