"The Man That Corrupted Hadleyburg" is a work of short fiction and satire. As a satire, the story presents an account of the downfall of Hadleyburg, "the most honest and upright town in all the region around about," along with its nineteen prominent citizens, in a dramatic, humorous, and often ironic fashion—the moment the town's Nineteen find themselves with a compelling reason to lie. In this way, Twain uses satire to expose and critique the human propensity toward temptation and greed, even at the expense of any semblance of virtue, when presented with the promise of great wealth.
Twain's work also adheres to the conventions of the 19th-century literary Realist movement, which prioritizes simple, realistic portrayals of human life in a story over the use of the fantastical or supernatural to advance the narrative. The characters in "The Man That Corrupted Hadleyburg" may be deeply flawed, but their behavior is believable—this is a simple story of a simple town whose citizens Twain shows to be very, very human and therefore very, very susceptible to temptation. Twain's commitment to realism ensures that his warnings about human vanity, and the moral elements of his story, are not lost on the reader.
