This awesome park ranger gave a great 30 minute explanation of the battle. (This video is only the last 3 minutes or so). First he told us about the events and history leading up to the battle and the personalities involved on each side of the war. Then he laid out the important geographic elements of the battlefield - a blue rope for the Potomac River, a blue rope for Antietam creek, a brown rope for each of the roads, a wood block for the Dunker Church and wood bridges for the three key bridges across Antietam Creek. (less info)