When General Lee entered Maryland he envisioned fighting a general battle north of the Potomac. Battle was the only way he might paralyze McClellan's army and gain the time he needed to replenish his army's strength to operate on the offensive again. The only practical place to engage McClellan in battle, given the condition of his army, was behind the Antietam.
In the face of the enemy, General Lee was by nature recklessly aggressive but not crazy. He had to clear his rear of the enemy garrison at Harper's Ferry before committing his army to the battle. Given the factors of time and distance this could not be done in the ordinary course of things, because McClellan would learn from reports almost immediately that he had split his army into wings, sending one of them to converge on the Ferry.
Lee knew that any reasonably intelligent general in Mac's shoes would react to this by pushing a heavy force toward the Ferry (through Crampton's Gap), tripling the threat the garrison posed to his line of retreat. If this happened Lee knew he would have no choice but to withdraw his other wing from Maryland—followed by McClellan—and either retreat toward Winchester or fight McClellan somewhere in the open rolling countryside of the Shenandoah Valley. This was the last thing he wanted to do; under the circumstances, he needed to rest his army in the Valley, not be pressured by the enemy to fight a battle there where his flanks could be so easily turned by their superior numbers.
Lee had to do something to prevent Mac from rushing a heavy force toward Harper's Ferry, had to do something to induce him to direct the weight of his army (through Turner's Gap) toward Hagerstown instead. The only possible way to induce Mac to do this, was for Lee to disclose to Mac where he was, where his "main body" was, and where his trains were. Knowing these three facts, Mac would naturally assume that the force remaining with Lee in Maryland had to be at least as strong as his own, poised to attack his flank and rear if he moved toward the Ferry. With Mac assuming this, Lee could expect him to move toward Turner's Gap to confront the danger directly.
But how to communicate this information to McClellan? Someone acting as a deserter might be sent to tell the tale to McClellan. But how credible would the deserter's story be to Mac? How about Mac's people finding this information by accident, say by discovering a lost copy of the army's general movement order? More credible? Certainly, if the circumstances in which it was found and its contents gave the appearance of legitimacy. And Mac would learn nothing about the actual strength of the enemy, only that the enemy intended to operate on the offensive against him as he attempted to cross South Mountain and enter the Cumberland Valley.
How to do it though. Stonewall Jackson is the key: He had a friend in the good Reverend Doctor John Ross, pastor of Frederick's First Presbyterian Church, and he was the brother-in-law of D.H. Hill. Ross, or some other trustworthy civilian, perhaps the Frederick lawyer William Ross, could easily plant the order in the path of the enemy. And D.H. Hill's name on the order would make it appear genuine. What could Hill do, if Jackson handed him a movement order, which he could see was written in Jackson's own hand, and told him he had better make sure he preserved it because his receipt of it would become a big issue someday? Hill would be naturally suspicious.
Why would Jackson waste his time writing out paragraph after paragraph of the order? That's the job of his staff. And why would Jackson suggest Hill keep this particular order in his personal, instead of official, papers? Something plainly was going on here that was out of the ordinary. But what could Hill do about it at the moment? Cross-examine Jackson? That would get him nowhere. Go to Lee and demand an explanation? Hardly. Lee did not like Hill and Hill did not like Lee. Lee expected his general officers to execute orders, not whine or complain about them. Hill was a whiner, a know-it-all. No sooner was the Battle of Antietam over with, than Lee had Hill conveniently removed from the army, sent back to North Carolina where Hill played out the war (except for a brief foray in the West), out of Lee's sight and out of mind.
Lee had to do some dancing to carry the ruse off: His adjutant, Walter Taylor, had the job of supervising the copying and transmission of movement orders. Lee got him out of the way by sending him off to Virginia on September 9th. This left Lee in control of the process and he used his control to play one side of his HQ staff—the Confederate Assistant Adjutant General's, Robert Chilton's, staff—against his personal staff officers—A.L. Long, Charles Marshall and Charles Venable.
Lee had one of Chilton's men, A.P. Mason, write out Taylor's detachment order as Special Order 191; then he had Charles Marshall (in Taylor's absence) write out the movement order as Special Order 190. Both of these orders were signed by Chilton and sent to Richmond, the first to General Cooper's, the Adjutant General's, office and the second to Jefferson Davis. Then Lee had Mason copy Marshall's version into Chilton's letterbook, which Mason did by adding Marshall's text to the text of Taylor's detachment order.
In this way, to the eye of Chilton and the other staff officers, nothing would seem amiss. Chilton knew that two distinct orders had been sent to Richmond, as required by Confederate Regulations, and that both had been copied into his letter book. Some form of an order, Chilton knew, was sent by courier to Walker whose division had been detached from the army on the 9th and had marched back to the mouth of Monacacy River, to guard the river road. But there is no credible admissible evidence, in any form, testimonial or documentary, which establishes the fact that additional copies of the movement order were prepared by any of Lee's staff officers and delivered to Lee's division commanders. Longstreet, in his autobiography alludes to receiving such an order, but it ought to be plain to the objective reader, from Longstreet's choice of language that he was merely going along with the conspiracy of silence that developed after the war, with his tongue in his cheek.
Who wrote McClellan's copy? Whoever wrote it, it was plainly copied from the copy Stonewall Jackson made for Hill. One need only compare Jackson's text of paragraph six of the movement order with Mac's copy and compare these two to the text of Marshall's and Mason's copies. Given the similaries between McClellan's copy and Lee's writing shown by the text of his letter to D.H. Hill, in 1868, Lee cannot be ruled out as the writer of the lost order; nor can Stuart whose pencil-written field notes, written to Lee in 1864, create an impression of similarity with the writer of the lost order.
Why the myth of the lost order? Plainly, the myth of the lost order arose out of General Lee's silence. Lee left the story of the lost order in the hands of Mac and his officers. It is their story that became public in the fall of 1862. Nothing was written about the issue of the order's loss in any of the Confederate reports. Jackson's report was not disclosed until after his death, in April 1863, and its text stops short of explaining his involvement in the planning of Lee's ruse. Lee's report is likewise silent as is Stuart's and Fitzhugh Lee's.
Since Jackson and Stuart were dead by 1864 there was nobody alive who could testify from personal knowledge that the loss of the order was a ruse, except Lee and the civilian who planted it, presumably Dr. Ross. Based on what little record exists of him, it is clear Ross was an unreconstructed rebel down to the day he died. With Jackson and Stuart dead, what could Ross have done about making public his role in the matter? He could expect that Lee would deny knowing anything about it. In 1867, in a letter to D.H. Hill, Lee denied he had any knowledge of how the order was lost, which means in a court of law merely that he left that issue to Jackson to handle.
The myth has persisted for almost a hundred and fifty years because no one writing about the subject has taken the time to gain personal knowledge of the three official copies implicated in the creation of Lee's lost order—the two orders signed by Chilton and sent to Richmond plus Mason's copying of these into Chilton's letterbook. Nor did anyone, who actually knew Chilton's handwriting, as far as the evidence shows, go to McClellan and look at the writing of his copy. (D.H. Hill wrote to McClellan, in 1867, asking questions about how it was found and Mac responded, but gave no intelligent answers.)
In the late 1870s, the process of collecting Confederate papers for inclusion in the Official Records of the Rebellion began. By 1886, the publication of these records reached the period of the Sharpsburg Campaign and at that time the two paragraph version, the ten paragraph version of Chilton's letterbook, and McClellan's copy reached the public view—but only as printed text. Hill's copy did not surface in public view until the 1930s; Davis's copy not until the 1940s.
Before the publication of the Rebellion Record, Walter Taylor—the one staff officer not present at Frederick after September 9th—injected the statement of "accident" into the lost order story which the historians and civil war writers of three generations have uniformly clung to in keeping the myth alive. In 1878, Walter Taylor was the first among Lee's staff to publicly assert the proposition that the order was lost by accident. In a footnote, Taylor claimed to report a statement made to him by Charles Venable. "Colonel Venable, one of my associates on the staff of General Lee, says in regard to this matter," Taylor wrote; "This is very easily explained. . . One copy was sent directly to Hill from headquarters. . . . [This copy] was undoubtedly left carelessly by someone at Hill's quarters." Eight years later, as the Rebellion Record was being published, A.L. Long repeated verbatim Venable's hearsay statement, in his Memoirs of Robert E. Lee. The whole basis of subsequent repetitions of the lost order story, up to today, is this hearsay statement.
Charles Venable is an enigma in this. As far as the evidence shows, he never publicly or privately denied or confirmed that this statement was in fact his. A professor of mathematics at the University of Virginia after the war, well connected by marriage to Old Virginia, he lived into the 1900s. What did this witness actually know? How did he know a copy of the order had been sent from Lee's headquarters to Hill's, much less that it was "undoubtedly left carelessly by someone at Hill's quarters?" Is the basis of his supposed statement merely his belief that a copy of the order was sent because such orders were, under Confederate Regulations, ordinarily sent? Or did he know a copy was sent because he supervised its preparation and transmission? Or was he speculating merely? The evidence of the historical record does not say.