No One Received a More Important Command: A Comparative Analysis of the Army of the Potomac’s and the Army of Northern Virginia’s Commanding Machines at the Battle of Gettysburg

This dissertation is a comparative case study of field army command during the Battle of Gettysburg in July 1863. At the Battle of Gettysburg, the Army of the Potomac (AoP) and Army of Northern Virginia (ANV) were physically, organizationally, and in spirit similar. Because of their similarities, the intangibles of leadership held an outsized impact on the battle’s results. Leaders and their commanding machines, comprised of senior subordinates and staff officers, pursued victory by applying lessons from the past, anticipating future events, and reacting to circumstances as they unfolded. Those commanding machines differed in three critical respects: 1) staff structure and organization, 2) personnel expertise and capacity, and 3) command processes that used the personnel and structure to aid commanders manage information and deliver energy. Collectively, these differences, albeit occasionally slight, each favored the AoP. In the bloodiest battle of the war that strained the abilities and capacities of both armies, the AoP aggregated those advantages over three days to achieve their first major victory and a turning point in the Civil War.