One of the best Civil War movies is Glory, based on the story of the 54th Massachusetts. Mr. Broderick played its commander, Colonel Robert Gould Shaw. At the time, he had no idea that, on his father's side, he had a Civil War ancestor, whose name was also Robert. If you haven't seen it, this episode of Who Do You Think You Are is well worth the 45 minutes: Who You Are
You only have til February 5 to watch. The new season starts on the 4th.