An historical reenactment of the battle of Gettysburg on Janus (Army)

Utilizing Janus (A), we analyzed the decision made by LTG Richard Ewell at Gettysburg, PA on the evening of 1 July, 1863. At this time, LTG Ewell decided not to attack Culpʹs Hill. Instead, he waited until the next morning to attack, to permit the mustering of both artillery support and his third division, under command of MG Johnson. Many historians contend that this was a poor tactical decision and was a direct cause of the confederate loss at Gettysburg and possibly the war. We have investigated this issue using a combat simulation model called Janus (Army). uisite to the simulation, systems and weapons of the time had to be modeled in the Janus database. To keep this relatively manageable, we decided to model only the most significant system types on each side. These included the Confederate and Yankee soldier armed with a bayonet and a non-repeating rifle; the cannoneer and cannon (12 Ib ball and cannister-shot) on each side. In total, the simulation represented nearly 200,000 systems engaged at Gettysburg. udy employed a two level, two factor experimental design. The two factors were the presence of the corpʹs artillery and Johnsonʹs division. Both factors were relevant to the decision to delay the confederate attack. The levels corresponded with whether or not each factor was used in the simulation. In all, we conducted three replications of the following four design points (tactical alternatives) from which to base our conclusions: 1. Point 1 (B): Situation on 1 Jul 1863 (no change). Ewellʹs Corps attacks. Point 2 (B+A): Corps Artillery supports the attack. Point 3 (B+J): MG Johnsonʹs Division participates in attack. Point 4 (B+A+J): Corps Artillery supports and MG Johnsonʹs Division participates in attack. clude that LTG Ewell made the correct tactical decision. Without either his corps artillery or Johnsonʹs Division, the corps would have faced annihilation should he have attacked on 1 July. Had he had his corps artillery (6 guns), he probably should have pushed aggressively up the hill. If he had only Johnsonʹs division, he probably could have taken the hill but could not have held it as a tenable position for very long.