D. H. Hill was to occupy South Mountain, or Boonsboro Gap, as it was variously called. Longstreet's strong column was to be in the vicinity of Hagerstown, twelve miles from D. H. Hill's position. Proper directions were provided for Stuart's large cavalry force.
The army moved from Frederick under the confidential order. All should have gone well. The programme would have been carried out, the severed army reunited, with Harper's Ferry captured at it was, and once in front of the already half-beaten McClellan (who had succeeded Pope in command of the Army of the Potomac), what great victory would surely have awaited us! But fate or an unlucky chance decided otherwise. A copy of General Lee's confidential order was handed to McClellan when he reached Frederick. He says in his official report that it was picked up by one of his men on our late camping ground.
Had Lee whispered into the Federal General's ear his inmost plans the latter could have asked for nothing more than the information brought him on that fatal paper.
The effect on McClellan was immediate. His march, up to then, had been cautious and timid, not more than eight or nine miles a day. When the order came to him he knew all about us. He knew that D. H. Hill's five brigades at Boonsboro would be nearly all that lay in his path to cross the mountain, and he began footing it with great speed. His march was rapid, and for McClellan confident. He actually struck D. H. Hill on September 14, on the mountain, with an overwhelming force. Hill defended himself valiantly, Drayton's and Anderson's brigades reinforcing him.
Hearing his guns near Hagerstown, Longstreet's quick military instinct told him what was happening. We instantly broke camp and raced out for Hill's relief. The distance was covered in extraordinary time and we happily got to Hill just as he was being driven from the crest of the mountain, and in time to save him. Darkness coming on, he was able to assemble his shattered battalions below, where with our force a front was shown that McClellan hesitated on immediately attacking. At sun up we prepared to move and were soon on the march to Antietam Creek, behind which part of the army took position on the 15th and 16th.
But I must go back to Frederick City, asking how a document so vitally important as General Lee's order could have suffered loss. It has often been discussed in special papers, in magazine articles, and in letters. McClellan says it was addressed to Major-General D. H. Hill. There is no disputing this because the document is on file for evidence. General Hill and his adjutant-general, Col. Archer Anderson, both declare it impossible to have been Hill's copy. They are to be implicitly believed. In addition, Colonel Anderson is able to produce a copy addressed to his chief.[1] Thus we find ourselves in a dilemma.
The explanation suggested is that perhaps two copies were sent Hill. Although now an independent division, Jackson considered Hill under his command and sent him a copy of the order. One copy certainly reached him direct from General Lee. Jackson and Hill, although connected by marriage, had it is said no great personal liking for each other, and I can imagine the cross and dyspeptic Hill, with the order from Lee in his pocket, receiving another copy from Jackson with careless irritation. If this theory does not work out, we seem to be quite baffled in finding a solution.
We had a bad night on the mountain, extracting D. H. Hill. He had made a magnificent defense, but was terribly mauled and broken up.
Drayton's brigade had been dispersed. There was great straggling to the rear by some of the men and our staff had to make sharp play with the flats of our swords on the backs of these fellows. It tired and disgusted me. The mountain roads were filled with broken regiments and companies and it was very late before they got to the foot of the mountain and in some sort of order. The material of our army was such that it did not take long for the men to shape up after disaster. It was near daylight before I got to Longstreet's bivouac, made a brief report of things, and threw myself on some fence rails in the bad weather for a chance to sleep. Not for long, however. All hands were soon afoot preparing for the march. During the day I came up with my old friend and schoolmate "Sandy" Duncan, of the Hussars. He was a comical object, but doing good service mounted on a little beast, almost skin and bones, with scarcely any hair. The animal looked badly scalded. He bore Duncan and his arms however, the trooper bearded and with as odd an appearance as his mount. He was gathering stragglers and pushing them forward with hard words and sometimes blows. We had never a campaign when there was so much straggling. Duncan was an excellent cavalry soldier and devoted to his troop. In full health to-day at Savannah, he is considered justly good authority on all things Confederate.