Garry Adelman, a historian, rates American Civil War battles in movies. He breaks down the military strategy seen in the battle scenes in “Gettysburg” (1993), starring Jeff Daniels. He also separates fact from fiction regarding Civil War-era surgeries as seen in “Dances with Wolves” (1990), starring Kevin Costner. Adelman is the chief historian at the American Battlefield Trust. He has also been a licensed battlefield guide at Gettysburg National Military Park for 27 years. | Insider Entertainme