The correct answer here is the flashback. After the soldiers sent him over the bridge to hang we enter a flashback sequence where we find out how Peyton got to the point where we first meet him. We find out that he was tricked by a disgraced Union soldier and he interfered with the railroad and the punishment for that is death by hanging.
Each genre has different elements that make it that genre, look for the elements of the story to find It's genre. (Fantasy= talking animals, Sci-Fi= flying cars, etc.)
