A friend of mine posted this fascinating article from the Smithsonian about Anne Kelly Knowles, and her topographical research that uses GIS technology to reinterpret our spacial and visual understanding of phenomena as diverse as the spread of concentration camps in Nazi Germany to Robert E. Lee’s field of vision at Gettysburg. The latter item caught my eye in particular, since this precise issue was extensively debated during our staff ride to the battlefield this past July. We were assembled at the remains of…the Cadori farm, I believe…and discussing the different commanders’ decisions on July 2, when our leaders looked over toward the Lutheran Theological Seminary and commented on the fact that its cupola could barely be seen over the treetops. This led to larger discussion concerning what Lee could and could not see at Gettysburg, and, based on what we could see on the ground, he really had no clear field of vision over the Emmitsburg Road. This interpretation seemed to be confirmed by what we knew about his plan for Day 2: that Longstreet’s attack was meant to turn the Union left , which it would have once it reached the Emmitsburg Road. As Longstreet phrased it in his report: “I received instructions from the commanding general to move, with the portion of my command that was up, around to gain the Emmitsburg road, on the enemy’s left. The enemy, having been driving back by the corps of [LG] Ewell and [LG] A. P. Hill the day previous, had taken a strong position, extending from the hill at the cemetery along the Emmitsburg road” (OR, Series I, vol. 27, part 2, Longstreet’s report, 358-9).
The Wikipedia maps below show the plan versus the reality rather neatly:
Now, Sears, for one, believed that Lee could clearly see the line on Cemetery Ridge, and that the debate between Lee and Longstreet about whether McLaws’ division should be perpendicular or parallel to the Emmitsburg Road “was simply indicating the northerly thrust of his [Lee’s] design for assaulting the exposed enemy flank on Cemetery Reidge” (Gettysburg, 255-6). However, to the knowledge of everyone in the party, no one had ever tried to survey what Lee could and could not see. So, it’s quite fascinating to read that Dr. Knowles’ scientific analysis of the terrain confirms exactly this picture: Lee literally could not see past the fold in the ground just east of the Emmitsburg Road, even from his vantage point in the Seminary tower.
Now, of course this circumstance alone is simply one part of what happens on July 2, starting with the faulty dawn recon by Johnston and Clarke, who swore that they’d scouted the Peach Orchard and got up to the Round Tops, meeting only a Union cavalry patrol along the way. Which, as Sears points out (Gettysburg, 252-3), would have been impossible had they actually made it to the Round Tops–there was no way they could have missed some indication of the nearly two corps’ worth of Federal troops in the area. There is Longstreet’s delay, rerouting his troops behind concealing terrain, so as not to give away what the plan was, which resulted in the attack not jumping off till 4 p.m. And of course there is Sickles, who, against Meade’s orders, moved forward precisely into the line that Lee thought the Union army held. In the event, McLaws’ attack didn’t go in till 5:30, by which time Hood’s attack had been completely derailed by Union troops fed into positions well back from the Emmitsburg Road on Houck’s Ridge, Little Round Top, and then the Wheat Field.
The single “fact” that Lee could not see a significant portion of the field, and relied on faulty recon to make his plans, does not, therefore, constitute the magic key to explaining why he lost the battle (and July 3 is a whole other story besides). Battles are usually too complex for that, a much-studied one like Gettysburg especially so. But it does go a long way to explaining the basis and context of his decision-making–which is a much more effective way to study a battle than to search for “that one decisive factor.” Over-confidence in his troops, a dangerous contempt for the capabilities of the Union army, over-reliance on mission-type orders to his subordinates, and major health problems certainly influenced his decisions, as scholars such as Elizabeth Brown Pryor (352-60) have noted. But his being unable to physically see, and accurately assess, the battlefield, is an essential element in explaining the genesis of the subsequent narrative.