Almost every western series has this exact same plot. Ex Confederate POWs or soldiers don't like the way they and/or a family member were treated in a prison camp, so they decide to take revenge on the commander of the POW camp years after the war has ended. It doesn't matter how many years it's been since the war ended or if the former commander is sick or lame, the bullies have to take their revenge. Of course nothing is ever said about the treatment Union POWs received at the hands of the Confederates. It's always ex Confederate POWs who thought they were mistreated. They always seem to forget that supplies were short on both sides of the war.