Very Informative Article on How McClellan Outsmarted Lee at Antietam

It seems strange for Lee to move Longstreet to Hagerstown, increasing the distance between the divided parts of his army and only leaving a small force at South Mountain unless for some purpose PA or didn't the troopers that escaped for Harpers Ferry capture some of Lee's wagons at Williamsport? Possablely Longstreet was collecting ammunitiom and supply's.
 
It seems strange for Lee to move Longstreet to Hagerstown, increasing the distance between the divided parts of his army and only leaving a small force at South Mountain unless for some purpose PA or didn't the troopers that escaped for Harpers Ferry capture some of Lee's wagons at Williamsport? Possablely Longstreet was collecting ammunitiom and supply's.
Hagerstown wasn't a major depot, there wouldn't be any ammunition there. Foraging is possible, though Lee doesn't seem especially worried or especially elated about what he captured (he notes that he had a bit of a shoe problem, which sounds like a reason to go to Gettysburg to me! :wink: )
 
It seems strange for Lee to move Longstreet to Hagerstown, increasing the distance between the divided parts of his army and only leaving a small force at South Mountain unless for some purpose PA or didn't the troopers that escaped for Harpers Ferry capture some of Lee's wagons at Williamsport? Possablely Longstreet was collecting ammunitiom and supply's.

Yes, it was an ordnance train under Lt Francis W Dawson, and it was apparently Longstreet's divisional train.
 
Saphroneth you always seem to have good reply's. After last post I found out they did captured Longstreets reserve ammunition wagons, that were heading west ,redirecting them to Greencastle. They probably had already been in Maryland a good while.
 
Yes, it was an ordnance train under Lt Francis W Dawson, and it was apparently Longstreet's divisional train.
That's an interesting point, because as I understand the org chart Longstreet didn't have a division any more. Presumably when Longstreet's two demi-divisions were upgraded to full divisions the train just wasn't renamed, unless I'm misunderstanding the course of events.
 
That's an interesting point, because as I understand the org chart Longstreet didn't have a division any more. Presumably when Longstreet's two demi-divisions were upgraded to full divisions the train just wasn't renamed, unless I'm misunderstanding the course of events.

The 6 brigades commanded by DR Jones were still formally "Longstreet's Division". His (and Jackson's) status as formal Corps/ Wing commanders came in November with their promotions to Lt Gens.

Longstreet's command was formed from the following old divisions:

Kemper's Division (Kemper, Pickett and Jenkins) - this was Longstreet's original division that he commanded from late '61 onwards and went to Yorktown* ca. 17th April (when Kemper's Bde was AP Hill's and Jenkins' was RH Anderson's)

Wilcox's Division (Wilcox, Featherstone and Pryor) - this was formed as the 3rd Division, Army of the Peninsula during the early siege of Yorktown, although there had been a shuffle during the creation of single state brigades (Featherston's bde here is not that of April). Being in Longstreet's "Centre of Position", being the division guarding Wynn's Mill, it was incorporated into Longstreet's command.

Toombs' Division under DR Jones (Toombs and DR Jones) - these two brigades were GW Smith's division in late '61 along with Wilcox. They went down to Yorktown as a division, and remained as such.

Whiting's Division under Hood (Hood and Law) - these 2 bdes were Whiting's division at Dumfries in late '61 (with Hampton) and went to Yorktown as a division*

Drayton's Division (Drayton and Evans) - these 2 bdes were post seven days reinforcements and served together for a little more than a month before the division was dissolved and Drayton sent to DR Jones and Evans to Hood.

* Neither of these two starred divisions served a day in the Yorktown entrenchments. They were excess to requirements and kept in reserve positions way back from the line.

On paper Longstreet remained a division commander, albeit the most senior one present. The "divisions" of Kemper and Wilcox were Longstreet's division, and he had under him two addition two divisions missing their division commanders and commanded by the senior brigadier. Longstreet divested himself of Wilcox, and used the excuse to amalgamate Toombs' division with his own. The new division was administered by DR Jones as senior brigadier, but fought as two normal sized divisions. This may be because Jones was considered a particularly good officer - certainly although he'd been one of Longstreet's brigadiers for the whole war, he'd be shuffled around as an acting division commander constantly. It may be Kemper was not considered very good, and what Longstreet was doing was making sure an efficient administrator was in place.
 
Drayton's Division (Drayton and Evans) - these 2 bdes were post seven days reinforcements and served together for a little more than a month before the division was dissolved and Drayton sent to DR Jones and Evans to Hood.
This impelled me to check something, and I see that Evans was actually senior to Hood (due to an earlier dated BG promotion) - presumably this is why Hood and Evans were not formally all part of the same single division, as that would put Evans in charge of the result.
It's interesting that the AoNV operated under what were de facto "corps" arrangements for months before things were finally formalized, and more so that the split was not the same as the one which took place during the march on Harpers Ferry.
 
This impelled me to check something, and I see that Evans was actually senior to Hood (due to an earlier dated BG promotion) - presumably this is why Hood and Evans were not formally all part of the same single division, as that would put Evans in charge of the result.
It's interesting that the AoNV operated under what were de facto "corps" arrangements for months before things were finally formalized, and more so that the split was not the same as the one which took place during the march on Harpers Ferry.

Evans turned out to be a nightmare, and had Hood under arrest. Longstreet removed the brigade from the division and Hood reverted to command. Evans then commanded a new division made up of his own and DR Jones' (GT Anderson's) brigades.

Lee was never against multi-division formations. Longstreet's wing basically came into being as the troops Lee sent under Longstreet to operate against Pope in early August.
 
It seems strange for Lee to move Longstreet to Hagerstown, increasing the distance between the divided parts of his army and only leaving a small force at South Mountain unless for some purpose PA or didn't the troopers that escaped for Harpers Ferry capture some of Lee's wagons at Williamsport? Possablely Longstreet was collecting ammunitiom and supply's.
From Lee's report:
A report having been received that a Federal force was approaching Hagerstown from the direction of Chambersburg, Longstreet continued his march to the former place, in order to secure the road leading thence to Williamsport, and also to prevent the removal of stores which were said to be in Hagerstown.
 
Lee lays out the plan and purpose of the '62 Maryland expedition in his report. Threatening, not taking, Baltimore. Threatening, not invading Pennsylvania. Keep the federal army out of Virginia.

Here is what Lee wrote:
The war was thus transferred from the interior to the frontier, and the supplies of rich and productive districts made accessible to our army. To prolong a state of affairs in every way desirable, and not to permit the season for active operations to pass without endeavoring to inflict further injury upon the enemy, the best course appeared to be the transfer of the army into Maryland. Although not properly equipped for invasion, lacking much of the material of war, and feeble in transportation, the troops poorly provided with clothing, and thousands of them destitute of shoes, it was yet believed to be strong enough to detain the enemy upon the northern frontier until the approach of winter should render his advance into Virginia difficult, if not impracticable. The condition of Maryland encouraged the belief that the presence of our army, however inferior to that of the enemy, would induce the Washington Government to retain all its available force to provide against contingencies, which its course toward the people of that State gave it reason to apprehend. At the same time it was hoped that military success might afford us an opportunity to aid the citizens of Maryland in any efforts they might be disposed to make to recover their liberties. The difficulties that surrounded them were fully appreciated, and we expected to derive more assistance in the attainment of our object from the just fears of the Washington. Government than from any active demonstration on the part of the people, unless success should enable us to give them assurance of continued protection.
Influenced by these considerations, the army was put in motion, DH Hill’s division, which had joined us on the 2d, being in advance, and between September 4 and 7 crossed the Potomac at the fords near Leesburg, and encamped in the vicinity of Fredericktown.
It was decided to cross the Potomac east of the Blue Ridge, in order, by threatening Washington and Baltimore, to cause the enemy to withdraw from the south bank, where his presence endangered our communications and the safety of those engaged in the removal of our wounded and the captured property from the late battle fields. Having accomplished this result, it was proposed to move the army into Western Maryland, establish our communications with Richmond through the Valley of the Shenandoah, and, by threatening Pennsylvania, induce the enemy to follow, and thus draw him from his base of supplies.

There was no intention to take Baltimore or to launch a full-scale invasion into Pennsylvania.
 
There was no intention to take Baltimore or to launch a full-scale invasion into Pennsylvania.
So do you thus hold that Lee's primary or sole motivation was to remain in Maryland for the whole of the remaining campaign season, presumably to fight a battle to the west of South Mountain?
If so, then one might presume that Lee should be ready for a battle to break out once he threatened Pennsylvania (and his 'advance guard' indeed reached the state line), but he was not.

A report having been received that a Federal force was approaching Hagerstown from the direction of Chambersburg, Longstreet continued his march to the former place, in order to secure the road leading thence to Williamsport, and also to prevent the removal of stores which were said to be in Hagerstown.
Interestingly looking in the correspondence Lee declared his intent to move towards "Hagerstown and Chambersburg" as early as the 9th, though it's possible that only Boonsboro was meant.

Lee's report claims that the reason why South Mountain was not strongly held was that Lee desired to fight the Army of the Potomac as far as possible from Washington, though I have to wonder how true this is because it suggests Lee relied on his opponent advancing slowly; certainly Lee piled into South Mountain with almost everything he had available, though his report points out how much the Confederate cavalry slowed McClellan down.

Interestingly the comparison of Lee's correspondence of the 12th (before McClellan hit him) with his report (written after McClellan hit him) produces an apparent contradiction.
Lee's correspondence of the 12th declares that it was "always his intention" to march on Hagerstown even before he crossed the Potomac.
Lee's report declares that he only took Hagerstown to secure it from capture by a reported Federal force (which presumably didn't actually exist). The report in question doesn't seem to be in the ORs, but that doesn't necessarily mean much.


What this means then is that, per your interpretation of the situation, Lee:

- crossed the Potomac east of the Cacotins in order to menace Washington and Baltimore, and thus ensure the removal of enemy forces from Virginia.
- crossed west into western MD in order to firstly capture Harpers Ferry (to open a supply line west of South Mountain to support him in western MD) and secondly to threaten Pennsylvania, with the reason behind both of these to provoke a general engagement in western MD with the Army of the Potomac.
- was surprised badly by McClellan arriving several days before he was planning on McClellan arriving.

This is a plausible plan, but it has two problems with it - the first problem being that Lee declared himself to be so heavily outnumbered at Sharpsburg, and that he in fact spent the entirety of the 15th-18th withdrawing over the river. The question that this raises is simple - if Lee planned a battle in western Maryland, how exactly did he think this could possibly be won if he struggled so to hold off an attack by only a portion of McClellan's army on a series of strong defensive positions?
The second problem is simpler. McClellan sent off his force towards the Cacotins before SO191 was even obtained (Cox's division marching at about noon, and his not being the first force to depart as he was told about a mix-up ahead of him per his account) on the 13th, and it's a single long march from Frederick to Boonsboro - as Lee should have known as he'd marched it with Jackson and Longstreet on the 10th. Even if McClellan only made about eight miles a day instead of the fifteen that Jackson and Longsteet had managed, he should have known it was possible for McClellan to reach South Mountain on the 14th - thus threatening the rear of McLaws in the Pleasant Valley.

Thus, in order for Lee's timetable to hang together, he would have to have been planning on:

McClellan to move no further than Middletown on the 13th and no further than South Mountain on the 14th. (Two six mile marches, or two eight mile marches for a force moving on Cramptons Gap.)
Harpers Ferry to fall on the 14th. (A delay of a day would mean the loss of McLaws entire command.)
His entire army concentrated and able to offer battle before McClellan reached him, either at Sharpsburg or further north around Hagerstown.

Frankly this seems like Lee is sequencing events far too closely to be safe and completely disregarding what his enemy could possibly do to him, and it's because of the juxtaposition between Lee planning an engagement in western MD as his primary objective (by strongly provoking McClellan) and Lee being completely unprepared for McClellan to march more than half as fast as Lee did over the same route (despite enacting the exact provocation he was planning).
 
So do you thus hold that Lee's primary or sole motivation was to remain in Maryland for the whole of the remaining campaign season, presumably to fight a battle to the west of South Mountain?
If so, then one might presume that Lee should be ready for a battle to break out once he threatened Pennsylvania (and his 'advance guard' indeed reached the state line), but he was not.


Interestingly looking in the correspondence Lee declared his intent to move towards "Hagerstown and Chambersburg" as early as the 9th, though it's possible that only Boonsboro was meant.

Lee's report claims that the reason why South Mountain was not strongly held was that Lee desired to fight the Army of the Potomac as far as possible from Washington, though I have to wonder how true this is because it suggests Lee relied on his opponent advancing slowly; certainly Lee piled into South Mountain with almost everything he had available, though his report points out how much the Confederate cavalry slowed McClellan down.

Interestingly the comparison of Lee's correspondence of the 12th (before McClellan hit him) with his report (written after McClellan hit him) produces an apparent contradiction.
Lee's correspondence of the 12th declares that it was "always his intention" to march on Hagerstown even before he crossed the Potomac.
Lee's report declares that he only took Hagerstown to secure it from capture by a reported Federal force (which presumably didn't actually exist). The report in question doesn't seem to be in the ORs, but that doesn't necessarily mean much.


What this means then is that, per your interpretation of the situation, Lee:

- crossed the Potomac east of the Cacotins in order to menace Washington and Baltimore, and thus ensure the removal of enemy forces from Virginia.
- crossed west into western MD in order to firstly capture Harpers Ferry (to open a supply line west of South Mountain to support him in western MD) and secondly to threaten Pennsylvania, with the reason behind both of these to provoke a general engagement in western MD with the Army of the Potomac.
- was surprised badly by McClellan arriving several days before he was planning on McClellan arriving.

This is a plausible plan, but it has two problems with it - the first problem being that Lee declared himself to be so heavily outnumbered at Sharpsburg, and that he in fact spent the entirety of the 15th-18th withdrawing over the river. The question that this raises is simple - if Lee planned a battle in western Maryland, how exactly did he think this could possibly be won if he struggled so to hold off an attack by only a portion of McClellan's army on a series of strong defensive positions?
The second problem is simpler. McClellan sent off his force towards the Cacotins before SO191 was even obtained (Cox's division marching at about noon, and his not being the first force to depart as he was told about a mix-up ahead of him per his account) on the 13th, and it's a single long march from Frederick to Boonsboro - as Lee should have known as he'd marched it with Jackson and Longstreet on the 10th. Even if McClellan only made about eight miles a day instead of the fifteen that Jackson and Longsteet had managed, he should have known it was possible for McClellan to reach South Mountain on the 14th - thus threatening the rear of McLaws in the Pleasant Valley.

Thus, in order for Lee's timetable to hang together, he would have to have been planning on:

McClellan to move no further than Middletown on the 13th and no further than South Mountain on the 14th. (Two six mile marches, or two eight mile marches for a force moving on Cramptons Gap.)
Harpers Ferry to fall on the 14th. (A delay of a day would mean the loss of McLaws entire command.)
His entire army concentrated and able to offer battle before McClellan reached him, either at Sharpsburg or further north around Hagerstown.

Frankly this seems like Lee is sequencing events far too closely to be safe and completely disregarding what his enemy could possibly do to him, and it's because of the juxtaposition between Lee planning an engagement in western MD as his primary objective (by strongly provoking McClellan) and Lee being completely unprepared for McClellan to march more than half as fast as Lee did over the same route (despite enacting the exact provocation he was planning).
Lee commented on how slowly the enemy was moving early in the expedition. Perhaps he mistakenly assumed they would continue to move slowly. No doubt he was relying on a razor thin margin of safety in order to concentrate in time.

Looking at a terrain map, the importance of Hagerstown and Sharpsburg and Harpers Ferry become clear, as completely covering the Valley and it's Potomac River crossings.
 
Looking at a terrain map, the importance of Hagerstown and Sharpsburg and Harpers Ferry become clear, as completely covering the Valley and it's Potomac River crossings.
True, but they're widely spread and without good routes between them (HF and Sharpsburg are most of a day's forced march apart, ditto Sharpsburg and Hagerstown). You can't really cover all the crossings while operating on the Maryland side, not without spreading the army significantly enough to render it vulnerable to an attack on either flank (or the middle), for that matter).
If Lee wanted to place himself so as to be ready for a movement by McClellan against him then he would have been better served by covering South Mountain strongly until Harpers Ferry was taken, then if he wanted to draw McClellan further from Washington than South Mountain he has to either leave some force at Harpers Ferry and concentrate in the Bakersville area, or somewhat uncover the crossings into Maryland again, or cover the crossings of the Potomac at Harpers Ferry north to Botelers Ford with troops in Virginia and concentrate somewhere aound Hagerstown - though this means that his actual force during the clash of arms would involve a smaller all-up army than he had historically.)

Lee commented on how slowly the enemy was moving early in the expedition. Perhaps he mistakenly assumed they would continue to move slowly. No doubt he was relying on a razor thin margin of safety in order to concentrate in time.
That's the thing, though, if Hagerstown was an opportunistic move on the 12th he could have moved back towards South Mountain on the 13th, thus allowing him to more strongly resist the enemy crossing South Mountain if they reached it on the 14th - because even if McClellan moved at only six miles a day then he'd threaten all three passes of South Mountain on the 15th, that's essentially impossible to avoid. It also means that the force-marches which weakened chunks of his army would have happened even if things had gone according to his plan.

If Lee intended to surrender South Mountain without a serious fight then that was a mistake - relying on such a razor thin margin of safety is not good generalship, especially when safer alternatives (holding South Mountain in strength until the HF operations are complete) exist. Lee was trained at West Point and in other instances he clearly follows the doctrine that one should entrench to multiply combat power with one's fixing force.

I suppose the question I have is where Lee was intending on concentrating, and when. If it was Sharpsburg then he got essentially exactly the battle he was planning on (with more of his force on the field than McClellan's, too) along with the advantage of the defence, and yet not only did it come out as a equal honours at best but it was one he spent the entire period before, during and after the battle moving away from. (Heck, it raises the question of why he didn't attack in the afternoon of the 17th or on the 18th... unless he'd found that he'd bitten off significantly more than he could chew in a field battle with McClellan.)
 
Here is what Lee wrote:

There was no intention to take Baltimore or to launch a full-scale invasion into Pennsylvania.

Only written eleven months after his defeat. Lee wrote this after the retreat from Gettysburg!

When one threatens something, if the action it should compel doesn't happen, for example, McClellan didn't move to block the route to Baltimore, then you can follow through on the threat.

Lee commented on how slowly the enemy was moving early in the expedition. Perhaps he mistakenly assumed they would continue to move slowly. No doubt he was relying on a razor thin margin of safety in order to concentrate in time.

Did he? On the 8th he wrote (wrongly) that the enemy hadn't moved from Washington. McClellan had already advanced his cavalry screen to contact and had moved Burnside with 1st and 9th Corps north to cover Baltimore. On the 12th he writes from Hagerstown that his advance forces have reached the Pennsylvania state line, but he's awaiting the capture of Harper's Ferry before continuing. When he wrote Davis on the 13th he literally had no idea McClellan was bearing down on him. On the 16th he wrote:

"Mr. President: My letter to you of the 13th instant informed you of the positions of the different divisions of this army. Learning that night that Harper’s Ferry had not surrendered, and that the enemy was advancing more rapidly than was convenient from Fredericktown, I determined to return with Longstreet’s command to the Blue Ridge, to strengthen D. H. Hill’s and Stuart’s divisions, engaged in holding the passes of the mountains, lest the enemy should fall upon McLaw’s rear, drive him from the Maryland Heights, and thus relieve the garrison at Harper’s Ferry."

In fact, McClellan's cavalry screen was so effective that Lee was utterly unaware that McClellan was coming in on him with five corps basically until they hit him at South Mountain.

Looking at a terrain map, the importance of Hagerstown and Sharpsburg and Harpers Ferry become clear, as completely covering the Valley and it's Potomac River crossings.

Sharpsburg is strategically meaningless. It was the only available fallback position that allowed McLaws' command to potentially reunite with the main army. Harper's Ferry threatened his supply line from Winchester, and he just needed the garrison gone. Hagerstown allowed him to move north into Pennsylvania, as he intended on doing.

His objectives were no different to June 1863. He just didn't get as far because the Federal commander was quicker.
 
If Lee intended to surrender South Mountain without a serious fight then that was a mistake - relying on such a razor thin margin of safety is not good generalship, especially when safer alternatives (holding South Mountain in strength until the HF operations are complete) exist. Lee was trained at West Point and in other instances he clearly follows the doctrine that one should entrench to multiply combat power with one's fixing force.

He intended to hold McClellan at South Mountain. He moved all available forces there, and you'll note that at Fox's and Turner's Gaps they did repel the 1st and 9th Corps. It was only 6th Corps that gained a gap. Find this out Lee quit his position because his rear was threatened.

The major difference is that Crampton's Gap was not reinforced. McLaws did not march any forces to reinforce it, and only 2 brigades defended it and they were covering almost a mile of frontage, i.e. what was appropriate for a corps. At the other two they had twice the manpower defending half the frontage, and could form an actual line of battle. Lee had no reason to think Crampton's wouldn't hold, and indeed with better leadership from McLaws it should have been held.
 
I note that Lee's message on the 13th to McLaws is basically "the enemy have doubtless reached Frederick by now", and his 10pm to McLaws (actually by Talcott) states that "he believes" the enemy to be moving on Harpers Ferry. At this point 9th Corps was actually at Middletown...
 
Only written eleven months after his defeat. Lee wrote this after the retreat from Gettysburg!
And yet Lee wrote of the same purpose before the expedition as well, on Sep 3, '62:

I therefore determined, while threatening the approaches to Washington, to draw the troops into Loudoun, where forage and some provisions can be obtained, menace their possession of the Shenandoah Valley, and, if found practicable, to cross into Maryland. The purpose, if discovered, will have the effect of carrying the enemy north of the Potomac, and, if prevented, will not result in much evil.
 
On the 8th he wrote (wrongly) that the enemy hadn't moved from Washington. McClellan had already advanced his cavalry screen to contact and had moved Burnside with 1st and 9th Corps north to cover Baltimore.

On the 8th, the advance was at Leesboro, only 8.5 miles from Washington. So maybe more accurately, Lee should have said the enemy had barely moved beyond the outskirts of Washington.
 
When one threatens something, if the action it should compel doesn't happen, for example, McClellan didn't move to block the route to Baltimore, then you can follow through on the threat.
Lee played McClellan.

Threaten Baltimore to get the federals away from Virginia? Check.

Threaten Pennsylvania to get the federals even further away from their base? Check.

McClellan did not outsmart Lee. He did exactly as Lee expected.
 
Sharpsburg is strategically meaningless. It was the only available fallback position that allowed McLaws' command to potentially reunite with the main army. Harper's Ferry threatened his supply line from Winchester, and he just needed the garrison gone. Hagerstown allowed him to move north into Pennsylvania, as he intended on doing.

His objectives were no different to June 1863. He just didn't get as far because the Federal commander was quicker.
Sharpsburg was close to the Shepherdstown crossing, which definitely had value to Lee.

Lee's '62 objectives were clearly not the same as '63, and if not for the lost order, McClellan would have been even slower.

One objective, to run out the clock on the campaigning season, would have been successful if not for Lincoln. According to Rafuse, McClellan had no desire to take the offensive after Antietam. It was Lincoln who ordered him to move again.
 
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