The screenplay is an adaptation by Dudley Nichols of "The Stage to Lordsburg," a short story by Ernest Haycox. The rights to "Lordsburg" were bought by John Ford soon after it was published in "Collier's" magazine on April 10, 1937. According to Thomas Schatz, Ford claimed that his inspiration in expanding "Stagecoach" beyond the bare-bones plot given in "The Stage to Lordsburg" was his familiarity with another short story, "Boule de Suif" by Guy de Maupassant, although Schatz believes "this scarcely holds up to scrutiny". Ford's statement also seems to be the basis for the claim that Haycox himself relied upon Guy de Maupassant's story. However, there appears to be no concrete evidence for Haycox actually being familiar with the earlier story, especially as he was documented as going out of his way to avoid reading the work of others that might unconsciously influence his writing, and he focused his personal reading in the area of history.