(part three of three)
What exactly the Lost Order told McClellan has been the subject of much heated debate and controversy almost from the moment he glanced its contents.
From an intelligence standpoint, the Lost Order was important to McClellan, but not as much as has often been portrayed. As stated in the previous installment of this series, the most perplexing part about the campaign thus far to McClellan had been what Lee’s movements, heading in two different directions, meant. Now, the Lost Order simply solidified in McClellan’s mind exactly what Lee’s odd movements were all about. “I obtained reliable information of the movements and intentions of the enemy, which made it clear that it was necessary to force the passage of the South Mountain range and gain possession of Boonsborough and Rohrersville before any relief could be afforded to Harper’s Ferry.”
Despite the clarification, the Lost Order was four days old when McClellan read it, and the wording called for the various parts of Lee’s plan to be achieved by Friday, September 12—the day before Union soldiers found the order.
Naturally, the first thing to be done was to get his cavalry chief Pleasonton to verify the days old order. At 3:00 pm, Chief of Staff Randolph B. Marcy updated Pleasonton’s mission. While time faded away as Pleasonton’s horsemen went about their business determining the veracity of the order, McClellan, now very aware of the possibility that Lee’s army may be divided in his front, pushed more of his army in that direction almost instantaneously.
While setting the van of his army in motion, McClellan continued to browse through the order. It did seem that the discovery was a great find, but for as much as it told McClellan of Lee’s thus far undetermined intentions, the fog of war did not dissipate away like an early morning’s blanket of haze.
First, the order—which had been addressed to Gen. D.H. Hill, dropped by someone in the Confederate army, and then scooped up by three Indiana soldiers—began with Paragraph III. Either the Confederate high command proved unable to perform a simple arithmetic function (a highly unlikely proposition) or there was more to the order than what McClellan held in his hands. What did the first two paragraphs say further about Lee’s intentions?
A simple glance in the Official Records reveals that Paragraphs I and II state nothing about Confederate plans in Maryland. For McClellan to have known that was an utter impossibility. Certainly, the unanswerable question hung over his head throughout all of this: what was missing from the Lost Order?
The wayward copy of Special Orders No. 191 also did McClellan no favors in the numbers department, already not one of the general’s best attributes. Earlier reports flooding into headquarters told McClellan of an enemy force numbering as high as 200,000 strong. By the end of September 13, McClellan lowered this estimate not quite by half, concluding the enemy in his front “amounts to 120,000 men or more.” The Lost Order does not mention anything of troop strength, but clearly designates five separate enemy columns before dropping in two vague references to the main body. Was the main body another column or one of the columns already mentioned, just by a different name? In addition, the very essence of Lee’s plan outlined in Special Orders No. 191 suggested a large number of Confederate soldiers in Maryland. Would the enemy divide itself into such disparate columns in a foreign land if it was such a small force? The Lost Order could not answer that question either.
Despite all of this, McClellan did plan an attack for September 14, armed with the solid information he did glean from Lee’s campaign plan. He began moving his forces into position on September 13 to carry the next series of ridges cutting north-south across the landscape of western Maryland. So if the Lost Order did not provide McClellan with all of the information that he might have sought from such a fortuitous find, what then did it do?
As September 12 ended, the Army of the Potomac’s goals were to push west from Frederick and gain possession of Catoctin Mountain, a natural defensive barrier buttressed even more by the Confederate cavalry guarding the mountain passes. McClellan hoped that by carrying this mountain, Pleasonton’s cavalry could be in position the next day to go up and over the next barrier facing him—South Mountain.
The battle of South Mountain occurred on Sunday, September 14, and probably would have happened anyway, though perhaps on a smaller scale, as a natural extension of the Federals’ westward movement from Frederick whether the Lost Order was discovered or not. In McClellan’s first written report of the campaign, dated October 15, 1862, he also rightly recalled that the first place he received “reliable information that the enemy’s object was to move upon Harper’s Ferry and the Cumberland Valley, and not upon Baltimore, Washington, or Gettysburg” was while in Urbana on September 12.
This is not to pronounce that the Lost Order had no significance whatsoever. Until that document came into McClellan’s hands, he was peering through the smoke screen attempting to derive the intentions of his opponent mostly unsuccessfully. Where the Lost Order proved crucial to McClellan’s intelligence reports was in its clear indication of what Confederate movements towards Harpers Ferry and the Maryland-Pennsylvania line meant. There were many other questions Special Orders No. 191 presented to the commanding Union general, but Lee’s intention no longer remained one of them.
The discovery of the Lost Order truly is an incredible story. Who could not indulge in a story like it? Its mysterious loss, the seemingly impossible find by three soldiers in a field, and its path up the chain of command right into George B. McClellan’s grasp accord the story a legendary status that few novelists could have framed better. Unfortunately, its import to the outcome of the campaign—and the war, say some—has been whisked into the legend of the Civil War.
Again, to say that the Lost Order’s odyssey is insignificant misses the point. To say that everything that subsequently happened in the Maryland Campaign hinged on this amazing story likewise does not stick to the track of the historical record. It is a story worthy of the ink spilled over its discovery, but does not accord it with the title of a major turning point of the Civil War.
 Report of George B. McClellan, OR, vol. 19, pt. 1, 26.
 Randolph B. Marcy to Alfred Pleasonton, September 13, 1862, 3:00 pm, OR, vol. 51, pt. 1, 829.
 Randolph B. Marcy to Jacob D. Cox, September 13, 1862, 3:35 pm, ibid., 827; Edward M. Neill to Orlando B. Willcox, September 13, 1862, ibid., 827-28.
 The full text of Special Orders No. 191 is found in OR, vol. 19, pt. 2, 603. The text of the Lost Order can be found in McClellan’s Report, OR, vol. 19, pt. 1, 42-43. The Lost Order reproduced in McClellan’s report omits the paragraph numbers, but the original copy of the Lost Order found in McClellan’s papers in the Library of Congress show the oddly numbered order, GBM Papers, LOC, reel 31.
 Andrew G. Curtin to George B. McClellan, September 10, 1862, 10:00 am, OR, vol. 19, pt. 2, 248.
 McClellan to Halleck, September 13, 1862, 11:00 pm, ibid., 281.
 In addition to the references previously cited in this work, George B. McClellan to William B. Franklin, September 13, 1862, 6:20 pm, OR, vol. 19, pt. 1, 45-46, also provides information about the Army of the Potomac moving into positions to strike at South Mountain and relieve Harpers Ferry on September 13.
 McClellan’s Report, ibid., 26-27.