"This Hallowed Ground" is a set of rules for American Civil War 15mm military figures. These rules are designed for grand tactical play. The scale is set at six turns per hour and one inch for twenty-five yards. Movement, fire, and morale are based upon the brigade (consisting of one to six regiments for infantry and cavalry.) Artillery is structured around a battery of four to six guns (represented by a single unit.) Included is a sample (and partial) Order of Battle for Gettysburg and a supplement for adapting the rules to fictious battles against forces loyal to the Emperor Maxmillian I of Mexico. These rules are quite comprehensive, including command control, weather and other random events (such as pre-battle disease), artillery crew casualties, the effects of unit training/experience, close action procedures, morale, sighting and line-of-fire, and much more. Three appendices are included: A graphic description of formations; a brief description for conversion to 25mm figures; and a glossary.