The story opens with the unnamed narrator recounting a summer sea voyage from Charleston, South Carolina, to New York City aboard the ship Independence.

The narrator learns that his old college friend Cornelius Wyatt is aboard with his wife and two sisters, though he has reserved three state-rooms.

Hardy explains that the box had, in fact, held the corpse of Wyatt's recently deceased young wife.

In writing "The Oblong Box", Poe recalled his experience while stationed as a soldier at Fort Moultrie many years earlier by setting the ship's embarking point as Charleston, South Carolina to New York.

[2] Just a few months before the publication of "The Oblong Box", Poe experienced his own sea voyage when he moved to New York via steamboat.

[13] He also notes that the protagonist is "bumbling" because he allows his personal opinions to taint the physical evidence, leading him to incorrect conclusions.

He wrote, "Though not a major work in the Poe canon, 'The Oblong Box' delivers, through the narrator's grotesque misinterpretations, a clever satiric version of the detective hero.

[15] A 1969 film directed by Gordon Hessler starring Vincent Price carries the name The Oblong Box.