Captain Samuel R. Johnston was an engineering officer in the Army of Northern Virginia during the Gettysburg Campaign, and it has long been questioned whether or not he was supposed to be the guide for Lt. Gen. James Longstreet’s troops on the afternoon of July 2, 1863. This discussion will focus on Capt. Johnston’s role as a reconnaissance officer and how well he carried out that assignment.
Not much is known concerning Samuel R. Johnston. He may have been a member of the Fairfax Cavalry before transferring to the Engineers. Although attached to Headquarters of the Army of Northern Virginia, he was often on detached service with Longstreet. He conducted reconnaissance at Savage Station and Malvern Hill (both done after the major engagements) and "rendered valuable service" to J. E. B. Stuart. Longstreet was indebted to several of Lee’s staff officers, including Johnston, "for great courtesy and kindness" on the battlefields of Groveton, Manassas and Antietam. During the Fredericksburg and Chancellorsville Campaigns, he helped to site artillery positions and conduct a reconnaissance of the enemy’s position. Johnston served on Lee’s staff and on detached service with Longstreet, until the end of the war. By late 1864, Johnston had risen to the rank of lt. colonel.
In Out-Post, Dennis Hart Mahan, an instructor at West Point, noted that there was no more important duty for an officer than that of "collecting and arranging the information upon which either the general, or daily operations of a campaign must be based." A reconnaissance was necessary because even a detailed map could "never convey all the information that will enable an officer to plan, even an ordinary march, with safety..." Mahan stated that a reconnoitering officer "should be known to be cool-headed and truth-ful; one who sees things as they are, and tells clearly and precisely what he has seen." Based on his previous record, Johnston appeared to be a good officer to conduct a reconnaissance at Gettysburg.
At the end of the fighting on July 1, Gen. Robert E. Lee did not know the location of the bulk of the Army of the Potomac nor how far south along Cemetery Ridge the Union line extended. Brig. Gen. William N. Pendleton, Chief of Artillery, conducted a reconnaissance on the evening of July 1, but only to locate artillery positions on the northern part of Seminary Ridge.
At about 4 A.M., July 2, Lee sent for Johnston to make a "reconnaissance of the enemy’s left and report as soon as possible." Johnston later wrote that he was joined by Longstreet’s Chief Engineer, Maj. John C. Clarke. D. H. Mahan wrote that the first duty of a reconnoitering officer was "to ascertain recisely the duty required of him; and what further should be done in case of certain contingencies that may, from the nature of the duty, be naturally looked for." Johnston stated that the only specific order he received from Lee was to "reconnoiter along the enemy’s left and return as soon as possible." Johnston claimed Lee said nothing about finding a concealed route for troops but that it had not been necessary "as that was part of my duty as a reconnoitering Officer, and would be attended to without special instructions, indeed he said nothing about the movement of troops at all, and left me with only that knowledge of what he wanted which I had obtained after long service with him, and that was that he wanted me to consider every contingency, which might arise." It appears from this statement that Johnston did not ask Lee for any clarification as to his precise responsibility on the morning of July 2.
Mahan wrote that a reconnoitering officer should obtain maps, a good telescope, aids for judging distances, writing materials, some good guides and "gain all the knowledge he can, from the local inhabitants at hand,..." Johnston stated that he was accompanied by Maj. Clarke and three or four other men (from what unit he did not say) as an escort. We can not be sure what if any equipment or maps Johnston had with him, but from his writings he does not mention talking with any of the local inhabitants.
Johnston’s was not the only reconnaissance Lee sent out on the morning of July 2. Gen. Pendleton and members of Lee’s staff were also out that morning. These groups probably went no further south along Seminary Ridge than Spangler’s Woods, due to the presence of Union skirmishers. This would have prevented them from observing the low ground just north of Little Round Top and given them a distorted image of the Union line. Pendleton wrote that Johnston was with him on the morning of July 2, a claim Johnston denied. If they were together it was only for a short time.
In a post-war letter to Maj. Gen. Lafayette McLaws, Johnston wrote that his route was about the same as Longstreet’s counter-march. If Johnston’s route led from Lee’s headquarters near the Lutheran Theological Seminary, he could have traveled south down the west slope of Seminary Ridge and into the Willoughby Run valley. This would have taken him past the Samuel Pitzer farm and the Pitzer Schoolhouse after about 3 miles (only partially following Longstreet’s march). He then turned east to ascend the west slope of Warfield Ridge, where McLaws formed his troops later in the afternoon. Then, "following along that ridge in the direction of the round top across the Emmitsburg road and got up on the slope of round top, where I had a commanding view." Johnston seems to be saying that from Warfield Ridge he crossed the Emmitsburg Road and went onto Little Round Top, at about 5:30 a.m. This does not seem possible in view of known Union troop movements.
Brig. Gen. John Buford had bivouacked on the left of the Union line on the evening of July 1 with two brigades (about 2600 men). He was patrolling the Union left on the morning of July 2 and had sent patrols out as far as Fairfield (possibly a portion of the 9 NY CA). Buford’s main line seems to have been located at or near the Peach Orchard with 2 US AR (A) in support. The 6 NY CA had bivouacked in the Peach Orchard on the evening of July 1 and the 3 IN CA had bivouacked for the night in "the woods near Round Top." It is possible that Buford’s cavalry screen was thin enough to have allowed a small group of riders to penetrate.
Brig. Gen. John W. Geary’s division of the Twelfth Corps (3964 men) had taken position of the Union left on the early evening of July 1. His troops were posted between Little Round Top and the George Weikert Farm. Two regiments (5 OH IN and 147 PA IN) were posted on Little Round Top (probably on the north slope) with skirmishers thrown forward. Geary wrote that he was relieved by Third Corps troops at 5 a.m. Maj. Gen. David B. Birney, Third Corps, reported that he relieved Geary at 7 a.m. or later.
The Third Corps (about 7,267 men) had been bivouacking to the north of Little Round Top in the area of the George Weikert Farm (clearly visible from Little Round Top). The Second Corps (about 11,350 men) had bivouacked about 3 miles from town (one mile south of the Round Tops) on the evening of July 1. The corps was up and ready to march by daylight on July 2. Advancing along the Taneytown Road (along the east base of the Round Tops) they first took position east of the Taneytown Road near the intersection of Granite Schoolhouse Lane. The head of the column should have been in this area by about 5:30 a.m.
Along with some stragglers on the Emmitsburg Road, there were at least 18,000 Union troops between the Emmitsburg Road and the Taneytown Road and between Little Round Top and the George Weikert Farm at the time Johnston claimed to have been on Little Round Top. This seems improbable, as according to Captain Lemuel B. Norton, Chief Signal Officer of the Army of the Potomac, a signal station was established on Little Round Top by 11 P.M. July 1, and remained open until July 6. The signalmen surely would have encountered Johnston. It is possible that Johnston, in order to avoid being seen himself, somehow skirted these troops and went to Big Round Top instead. Although offering a "commanding view", the thickness of the woods and Little Round Top itself, would have prevented Johnston from seeing much of anything north of this position. Yet, a Union officer, Captain Francis Donaldson of the 118th Pennsylvania, wrote that his regiment was sent to Big Round the following day (July 3) where they enjoyed, "a commanding view of the whole field." Is it possible that Johnston was able to see the Union line from the summit of Big Round Top if that is actually where he went? Was there a break in the trees that is not visible in period photos of the hill? No one can know for certain, but it may have been possible for Johnston to see what he claimed.
Johnston wrote that after leaving the Round Tops he rode along the base to beyond the area occupied by Hood’s Division and "where there was a cavalry fight (either Farnsworth or Merritt). He spotted three or four Union cavalrymen on the Emmitsburg Road and allowed them to pass before recrossing the road and then took "the most direct route" back to Lee’s headquarters. Johnston admitted that there was "the usual delay in finding headquarters." (Either Lee had moved his headquarters, which seems unlikely, or Johnston is implying, in an off-handed way, that he was lost. Not a good sign for a competent reconnaissance officer in open farm country.)
Johnston reported to Lee at about 7 a.m., having been gone for about 3 hours. (Since he did not have a watch, Johnston was unsure of the time.) Lee was in conference with Longstreet and Lt. Gen. A. P. Hill studying a map. Johnston sketched his route on the map and Lee expressed surprise at his having gotten so far. When Longstreet and Hill moved off Johnston and Lee "talked of the topographical features of the country." Lee then said he wanted Johnston "to join General Longstreet. No other instructions whatever were given me. I fully understood that to mean that I was to go with General Longstreet to aid him in any way that I could."
Johnston’s reconnaissance did not meet all the elements of a good reconnaissance, as outlined by D. H. Mahan. When Longstreet’s column was in danger of being spotted, Johnston seems to have been unable to suggest an alternate route. (One of the basic responsibilities of a reconnaissance officer.) He was able to tell Lee where the Union left was not located but he was unable to tell him precisely where it was located. (Two entirely different propositions!) It is also hard to understand how Johnston could have missed seeing and/or hearing almost 18,000 Union troops between the Emmitsburg and Taneytown Roads and between Little Round Top and the George Weikert Farm; especially if he reached the summit of Little Round Top as he claims.
It has been stated that Confederate staff work broke down during the Battle of Gettysburg and Johnston’s reconnaissance on July 2 appears to be the best example.