When setting the scene of the story, Hurst includes an allusion to World War I, as seen in the following passage:
And during that summer, strange names were heard through the house: Chateau-Thierry, Amiens, Soissons, and in her blessing at the supper table, Mama once said, “And bless the Pearsons, whose boy Joe was lost in Belleau Wood.”
World War I was a global conflict fought primarily between the Allied Powers (which included France and the United States) and the Central Powers (which included Germany and the Ottoman Empire). All of the “strange names” that Brother mentions here—Chateau-Thierry, Amiens, Soissons, and Belleau Wood—are real places in France where battles were fought in World War I. Many American soldiers, such as “Joe” referenced in this passage, ended up being deployed to France to defend their ally against German aggression.
It is likely that Hurst included an allusion to World War I in “The Scarlet Ibis” in order to both give readers a better sense of when in time the story takes place and to add another reference to death in the story to prepare readers for Doodle’s death to come. Just like the scarlet ibis’s death, the deaths of World War I soldiers hang over the story, adding to the unsettling and dark mood.