In "Occurrence at Owl Creek Bridge," Farquhar is a gentleman. Why might he be hanged?

Peyton Farquhar is a wealthy Alabama plantation owner is about to be hanged from a railroad bridge in Alabama because he attempted to set fire to the Owl Creek Bridge and act as a vigilant by acting on his accord. By this, he got caught because he is being fooled by a union soldier and processed as it is customary: death by hanging.