In Part 1, the narrator describes a man (Peyton) about to be hanged. He looks to be about thirty-five years old and from his clothes, the narrator concludes that he is a farmer. He does not appear to be a violent criminal. These are the general introductions. In Part 2, we learn that Peyton is a slave-owner and a supporter of Southern secession. He is unable to fight for the South (in the Civil War) and this has an effect on him because he wants to fight for the Southern cause. He "longed for the release of his energies, the larger life of the soldier, the opportunity of distinction."
Peyton did anything he could to be a part of the war effort. That is why when he learns that the Union is advancing, he decides to burn Owl Creek Bridge to slow their advance. He does this even though he knows being caught will result in a hanging. When he is caught and hanged, he imagines his escape. In his desire to get back to his wife and children, he shows that his love for his wife and children is the one thing that trumps his love for the South.
In historical hindsight, we can fault Peyton for being a slave-owner and supporting that institution. But we can also understand he was a part of his era and culture. In the course of the story, the narrator begins with a general description of "a man." We don't get Peyton's name until Part 2. Throughout the course of the story, Peyton is more and more humanized. He is a farmer who made a bad judgment in trying to take down the bridge. He loves his wife and children. His imagined escape shows his desire to return to them and his desire for life itself.
Using this information, you could come up with some different one-sentence statements about Peyton. Peyton's love for his family and the South nearly enabled him to imagine his way out of certain death. Petyon is one of thousands of vibrant, flawed, faithful human beings who died in the Civil War.