1862 Loudoun Valley campaign

Jamieva

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Using this as a placeholder. There will be a c span video debuting this weekend with a talk from the Emerging Civil War Symposium. I want to use that as a tool to talk more about these actions. They are often overlooked. Most books about the eastern theater go straight from Antietam, the Mac/Burnside transition and then Fredericksburg.

Much like the actions between Gettysburg and the winter of 64-65 that Jeffrey Wm Hunt has covered in his books so well, these are movements that could use more study.

 

Jamieva

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Midlothian, VA
Just watched it, here is the Cliff' Notes version.

The Army of the Potomac post Antietam is not well supplied, per McClellan. There are soldier accounts to back this up. Stuart goes on his Chambersburg raid, which rides around the AotP, and he brings a lot of prime Pennsylvana horses with him. The AotP was counting on those to refit the cavalry, artillery, etc

At first, McClellan is told that Lee has abandaned the Shenandoah Valley, but 2 reconnaisances in force prove this false. Lee's army is in the Winchester/Martinsburg area of the lower valley.

The Loudoun Valley is bordered on the east by the Bull Run/Catoctin Mountains, and on the west by the Blue Ridge.

Lincoln sends a letter to McClellan pointing out he is closer to Richmond than Lee and if he can move quickly, he can force Lee to him and fight where he wants to. Mac waits 9 days to act on it.

The initial plan is to cut loose from their supply base and carrying 10 days rations/supplies, to try to reach the Manassas Gap rail road. Porter has the II and V corps on the eastern edge of the Blue Ridge, and their orders are to plug all the gaps into the Shenandoah Valley. Burnside has the I VI and IX corps moving down the eastern edge of the Loudoun. Sigel is to bring the III and XI Corps and meet them later at Thoroughfare Gap.

McClellan gets a 2 day head start, because Lee is not sure if this is a faint or a legit movement. Longstreet is ordered to move from Winchester to Front Royal, cross the Blue Ridge and then establish a blocking position at Culpeper Court House. Jackson stays in the Shenandoah to threaten the AotP flank and look for chances to pounce through the gaps.

The major combat of the campaign is the battle of Unison. A cavalry engagement that runs for 3 or 4 days. Pelham just as at Fredericksburg shines in a daring move off the Confederate left flank and rakes the Union forces. Stuart is fighting for time not space and falls back 6 times, ultimately stopping at Upperville.

The AotP reaches the Manassas Gap on November 4 and 5, but Longstreet had already reached Culpeper on November 3. Once this news reaches Washington, Lincoln decides to relieve McClellan.
 

Jamieva

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So here is where I want to try to kickoff our discussion. McClellan has a shorter distance to cross, and a 2 day head start.

So what causes Longstreet to beat him to Culpeper CH? Is it simply a matter of Mac being Mac and being a little slow? Did Longstreet push his corps ala Jackson's foot cavalry and fatigue the daylights out of them to get there?

If anyone has any recommended reading for this campaign please pass along.
 

Saphroneth

Major
Joined
Feb 18, 2017
So here is where I want to try to kickoff our discussion. McClellan has a shorter distance to cross, and a 2 day head start.

So what causes Longstreet to beat him to Culpeper CH? Is it simply a matter of Mac being Mac and being a little slow? Did Longstreet push his corps ala Jackson's foot cavalry and fatigue the daylights out of them to get there?

If anyone has any recommended reading for this campaign please pass along.
My understanding is that the causes for the 'delay' are:

1) McClellan is crossing a wide river (meaning one which requires bridging) - which means that McClellan has to feed his troops over the bridges, a process taking several days (the vehicles have to go over a single pontoon bridge in single file, which takes more than a day per corps), and that he can't start advancing until he has enough force south of the river to be able to fight if Lee is coming into Loudoun to fight. If McClellan sends his first corps over the river (9th) south without properly supporting them then there's the danger Lee will crush them.

2) Relatedly, McClellan is making an "advance to contact", as in, he does not know for sure that Lee is not ahead of him and waiting to fight. This means that McClellan's forces have to be in position for mutual support and advancing down parallel roads; Lee on the other hand is moving through territory that he knows is clear of Union troops, and so can just route-march down to Culpeper on the most direct route.

3) McClellan's flank is threatened by Jackson in the Valley. This means that components of McClellan's army have to sieze the gaps in the Blue Ridge mountains, wait there while the rest of the army moves past, and then pull away; their routes don't look like a straight line march because they're not.


From crossing the Potomac at Harpers Ferry to reaching Warrenton the 5th Corps (for example) marches 12 + 11 + 8 + 0 + 0 + 13 + 13 + 8 + 6 miles in nine days to reach Warrenton - a total of 71 miles, to do what would be only about fifty miles on a route march - because this includes a detour to Snickersville and two days holding position to defend Snickers' Gap. Thus the need to manoeuvre and hold the gaps adds four days to the journey (two days holding position, two days' extra marching at 10 miles per day while moving).

If McClellan and Lee had "raced" for Culpeper, both of them moving in a single column, then McClellan's head of column may well have got there first - but at the cost of being highly vulnerable in the process, which would mean Lee could instead just fall on the vulnerable and strung-out Union column and inflict a swingeing defeat.


Now, when Burnside moves from Warrenton down to the Fredericksburg area, he has no major rivers to cross and he knows there are no Confederate forces in the area, and he doesn't have to manoeuvre to prevent an attack by Lee. Consequently he can route-march down the direct route rather than advance-to-contact with forces ready for mutual support, and can move faster (though it helps that his men are well rested as a result of being at Warrenton for the previous week).
 

Saphroneth

Major
Joined
Feb 18, 2017
The timings of the movement to Culpeper:

On 28th October is when Lee orders Longstreet to move to Culpeper.
Longstreet starts at Martinsburg
Longstreet goes via Winchester, Newton, Front Royal, Chester Gap, Little Washington, Sperryville, to Culpeper and arrives there on the 5th (so marched on the 28th, 29th, 30th, 1st, 2nd, 3rd, 4th, 5th?) Which is about 90 miles in eight days, some of it on the Valley Pike.
Not sure the exact stations of the march, though it's a route a long way away from the one McClellan et al were taking so it's not like it hugely matters.


This basically means that when Longstreet started moving only 9th Corps was over the river; I believe it's the case that McClellan paused his movement for a day around this period because of the possibility that Lee was going to strike north (a rumour which was investigated by a cavalry recce) but even without that 1st Corps was still largely north of the Potomac when Lee started moving.


Interestingly 5th and 6th Corps were covering the upper Potomac against the threat posed by Longstreet; 5th Corps was pulled away on the 29th, in reaction to Longstreet's movement, and 6th Corps on the 31st.



Lincoln sends a letter to McClellan pointing out he is closer to Richmond than Lee and if he can move quickly, he can force Lee to him and fight where he wants to. Mac waits 9 days to act on it.
Something I do want to point out here is that as of when Lincoln sent that letter McClellan was actually under orders (from Halleck, his superior) not to cross the river.


It's a complex topic, but to sum it up with only the most important communications in this period:

7th October - Halleck tells McClellan that he can either go east or west of the Blue Ridge, and that Lincoln would prefer him to go east of the Blue Ridge but did not order it. He also orders McClellan to tell Halleck what he plans:

You will immediately report what line you adopt and when you intend to cross the river; also to what point the re-enforcements are to be sent. It is necessary that the plan of your operations be positively determined on before orders are given for building bridges and repairing railroads.
Obviously, this means that McClellan can't cross the river until his plans are approved - he needs permission to build the bridges required to cross.

McClellan immediately replies with his plan (at this point he wants to cross into the Shenandoah). Halleck does not reply.

16th October - Lincoln's letter about distances (where, of course, Lincoln doesn't understand how long it takes to cross a river).
17th October - McClellan replies to Lincoln, saying that he's not wedded to any particular plan and will either follow Lincoln's plan (once his army is properly supplied) or explain why not. He also gives Lincoln the opportunity to make his plan into an order.

21st October - Halleck reiterates his instructions of the 7th. To Lincoln, this means "move now", but the instructions that Halleck actually gave McClellan were to send his plan for approval and that nothing was to be done about bridges until approval was given.
McClellan replies by saying he'll follow Lincoln's plan.
23rd October - Halleck approves this plan.
The bridge at Berlin is started on the 24th and the first troops are over the river on the 26th. (I don't have data for the bridge at Harpers Ferry over the Shenandoah, but 2nd Corps crossed it around the 30th.)

On the 26th, Halleck states that he gave McClellan no orders, only "advice and suggestions".
 

Joshism

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Location
Jupiter, FL
1) McClellan is crossing a wide river (meaning one which requires bridging) - which means that McClellan has to feed his troops over the bridges, a process taking several days (the vehicles have to go over a single pontoon bridge in single file, which takes more than a day per corps), and that he can't start advancing until he has enough force south of the river to be able to fight if Lee is coming into Loudoun to fight. If McClellan sends his first corps over the river (9th) south without properly supporting them then there's the danger Lee will crush them.

Why couldn't McClellan's AOTP rapidly throw up numerous pontoon bridges? The only thing that delays Burnside at Fredericksburg was the pontoons not arriving on time and Confederate resistance on the south bank. The Union showed numerous times during the war that it could perform rapid and remarkable engineering feats.
 

Saphroneth

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Feb 18, 2017
Why couldn't McClellan's AOTP rapidly throw up numerous pontoon bridges? The only thing that delays Burnside at Fredericksburg was the pontoons not arriving on time and Confederate resistance on the south bank. The Union showed numerous times during the war that it could perform rapid and remarkable engineering feats.
The Potomac is a wide river and pontoons are in limited supply. In fact it's the same pontoons used for the bridge at Berlin and the crossing at Fredericksburg - 61 of them in the one bridge for the Potomac crossing:
Potomac bridge
berlin_oct_1862-jpg.jpg


My offhand count based on a photo of the Fredericksburg pontoons makes it look like it was less than half as many to cross the Rappahanock at Fredericksburg:

pontoon-bridges-ws-cu_9179.jpg

I count about 20 pontoons in each bridge, so obviously the same number of pontoons make more bridges; 100 pontoons would be enough for five bridges at Fredericksburg but only one over the Potomac. (The pontoons at Fredericksburg were supplemented by a second supply of them floated down from Washington, IIRC.)

ED: yep, 80 metres for the river at Fredericksburg and 240 metres for the river at Berlin. It's a simple river width issue.


On top of that one there were also pontoons needed to build the bridges around Harpers Ferry, which were to be left in place (as part of the defensive infrastructure).


So what actually happened was that McClellan threw two bridges over the Potomac, one at Berlin (for 1st and 9th Corps) and one at Harpers Ferry (which also crossed the Shenandoah river) for 2nd and 5th Corps. 6th Corps brought up the rear (having crossed at Berlin after the bridge was no longer in use), but by the time 6th Corps crossed the rest of the army was already on the move (having not waited until 6th Corps joined them); to get a much faster crossing to the point where the army could move south as an army you'd need at least another 60 pontoons to build a third bridge over the Potomac - that would get you a day or so, I think, though it's complicated by the fact that the same engineers who built the Berlin bridge would then need to build this additional one (and they took on the order of 24-36 hours to build the first one).
 

Saphroneth

Major
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Feb 18, 2017
I think even with one additional bridge you might not be able to speed things up by more than perhaps a day. There are two crossing columns, and if you speed one up then the other one becomes the limiting factor; you'd need one additional bridge at each location to be sure of getting acceleration.
Even then, it means you'd gain one or two days (if the bridges were created instantly when their counterparts were done and could be used in parallel). That means, all else being equal, you reach Warrenton on the 4th instead of the 6th; Longstreet reaches Culpeper on the 5th, so you still can't beat him there.
 

67th Tigers

1st Lieutenant
Joined
Nov 10, 2006
Pendleton was ordered to follow Longstreet once the road cleared. He was at White Post, just outside Winchester and recorded that the road clear at 1300 hrs, 1st November, allowing him to move. DH Hill's and Walker's divisions* were already at Upperville with FitzLee's cavalry screening him, as Lee had decided to reorientate his line and send Longstreet to the Potomac line east of the Blue Ridge. McClellan's crossing caused him to divert to Culpeper.

Walker's division marched south and arrived at Culpeper the evening of 2nd November. On the 4th November they marched to Cedar Mountain in the rear of Culpeper, and on the 8th to Madison Court House.

We know Pickett's division was under orders to move by forced marches, and straggled badly. Shades of the forced march to Sharpsburg. He arrived at Culpeper on the evening of the 2nd.

McLaws' division departed Winchester 31st October and arrived at Culpeper 4th November.

RH Anderson departed on the 1st, and arrived at Culpeper on the 5th.

Hood's division (only the Texas bde and Benning's bde) marched by Manassas Gap instead of Chester Gap, and arrived near Culpeper on the 5th. The other two bdes had a smallpox outbreak and marched via Swift Run Gap. The two bdes that went to Culpeper were encamped at Cedar Mountain.

Evans' bde was sent south on the 6th Novemeber.

* These two divisions were unitary under DH Hill until the corps structure was announced in early November. Then DH Hill was assigned to 2nd Corps and Walker to 1st Corps, with Walker being replaced by Ransom.
 

Saphroneth

Major
Joined
Feb 18, 2017
I take it from that then that we don't quite have enough information to do a location-by-day plot of the various components of Lee's army over the course of the Loudoun Valley campaign? (I suppose I could interpolate some of them.)
 

Saphroneth

Major
Joined
Feb 18, 2017
Here's an attempt:


McLaws:
Winchester to Culpeper in five marches (31st, 1st, 2nd, 3rd, 4th) would mean

Nineveh on the 31st
Chester Gap on the 1st
Little Washington on the 2nd
Lebanon Church on the 3rd
Culpeper on the 4th

RH Anderson:
One day behind McLaws

Nineveh on the 1st
Chester Gap on the 2nd
Little Washington on the 3rd
Lebanon Church on the 4th
Culpeper on the 5th

Half Hood:
Nineveh on the 31st
Linden Station on the 1st
Around Cobbler Mt on the 2nd
Amissville on the 3rd
Rixeysville on the 4th
Culpeper on the 5th


The other half of Hood kind of goes "off the map", presumably by the Valley Pike

Pickett:
Forced march from Martinsburg, presumably leaving Winchester during the 30th, if so:

Cedarsville on the 30th
Flint Hill on the 31st
Woodville on the 1st
Culpeper on the 2nd

Walker:
Paris on the 27th
Upperville on the 28th
Paris on the 29th
Paris on the 30th
Salem on the 31st
Between Waterloo and Jefferson on the 1st
Culpeper on the 2nd
Culpeper on the 3rd
Cedar Mountain on the 4th


In addition to this, I understand that AP Hill at some point is present near Snickers Gap and that DH Hill moves from Upperville to Front Royal over the course of the campaign, while Jackson and Ewell remain at Winchester.
DH Hill is at Ashby's Gap on 3rd November (at Paris after Walker leaves there?) then marches to Front Royal.
 

Saphroneth

Major
Joined
Feb 18, 2017
Particularly for the Confederates, these positions are somewhat tentative. However:


24th October (i.e. before the campaign itself starts)
loudoun_24th.jpg

I've co-located DH Hill and Walker because I have no better information. It is possible neither of them were here yet.

At this point both armies are in a defensive posture for the most part, along the upper Potomac. McClellan is spread out firstly because his intent up to this point was to strike into the Shenandoah (he switched plans in the last couple of days and got them approved late on the 23rd) and secondly because this way he can counter a move by Lee to cross the Potomac west of the Blue Ridge.
Lee is mostly covering the lower Shenandoah Valley, and is spread out partly to allow for forage. (Though Lee himself is actually down in Richmond.)


25th October:
loudoun_25th.jpg

9th Corps moves to Berlin, where the pontoon bridge is being set up. Not all the corps moves in one go, and the bridge is still being built.
I now have Walker localized so have put his force at Paris.



26th October:
loudoun_26th.jpg

1st Corps also breaks camp, concentrating on Berlin. 9th Corps pushes over the now-bridged river to control the debouche.
My guess based on the later movements is that the engineers may now have gone to Harpers Ferry to build the bridge over the Shenandoah, but this is not confirmed.


27th October:
loudoun_27th.jpg

9th Corps finishes crossing. 1st Corps has supply deficiencies to rectify, and does so while on the rail line; there is also some of the crossing of wagon trains here.



28th October:
loudoun_28th.jpg

Longstreet starts moving. (Some of the positions for Longstreet's movement are approximate.)
The news of Longstreet breaking camp causes McClellan to freeze his movement in case Longstreet is striking north (in which case he will need everything he has available north of the Potomac) and he sends a brigade-strength cavalry recce to investigate.




29th October:
loudoun_29th.jpg

With confirmation that Longstreet is not moving north, this is when the forces along the upper Potomac start peeling away. 9th Corps moves out to cover the whole of the upper Loudoun Valley (and possibly also to cover the terminus of the bridge at the mouth of the Shenandoah river).
This is the last point at which Pickett's position is estimated; after this point I'm pretty sure.


30th October:
loudoun_30th.jpg

1st and 2nd Corps cross much of their fighting echelon. Meanwhile Longstreet is moving south rapidly.


31st October:
loudoun_31st.jpg

At this point the only defensive forces along the upper Potomac are Morell's small force. 12th Corps is at Harpers Ferry and will be left there.
2nd Corps finishes crossing.
Walker begins moving south. All of what will formally be Longstreet's Corps next month are now on the move to Culpeper; Hood has split in half with the half going into quarantine assumed to be taking the Valley Pike route down to Swift Run Gap.


1st November:
loudoun_1st.jpg

5th Corps crosses much of their fighting echelon, and 6th Corps reaches the pontoon bridge. There are now four Union corps over the river and moving south.
The "traffic jam" at Jefferson is an approximation of position, and Pickett could have preceded Walker or they could have taken parallel routes. The position is only roughly correct.


2nd November:
loudoun_2nd.jpg


2nd and 5th Corps acting as a single wing under Porter seize Snickers' Gap (AP Hill is on the other side of it). 9th and 1st move past while the gap is masked.
6th Corps follows 9th and 1st.
There are now Confederate troops at Culpeper itself. Notably, DH Hill is still in a position to block the approach to Culpeper, which would let him at least delay a single-corps dash south.
At this point DH Hill is worried that Union troops may enter the Valley and cut off his retreat.


3rd November:
loudoun_3rd.jpg

5th Corps demonstrates against AP Hill, then returns to the gap. 9th and 2nd collect ready to go after Ashby's Gap, and push DH Hill away from his position at Upperville; the operations here are as much capturing the gap as if there'd been a major battle.
One division of 1st Corps is pushed forwards to take a crossing of Goose Creek.


4th November:
loudoun_4th.jpg

2nd Corps takes Ashby's Gap, and DH Hill pulls back into the Shenandoah before marching for Front Royal. 5th Corps is still holding Snickers' Gap.
Walker moves south away from Culpeper itself, which may indicate that Lee's plan is to keep moving south.



5th November:
loudoun_5th.jpg

9th Corps marches to take control of Manassas Gap. There are now Union corps controlling all the main gaps in the Blue Ridge Mountains, and meanwhile 1st Corps is preparing to take Warrenton.
Lee returns from Richmond (to Culpeper).


6th November:
loudoun_6th.jpg

With the bulk of the army past and 1st Corps taking Warrenton, the Blue Ridge mountain gaps are now no longer necessary. 2nd, 5th and 9th Corps all pull away from the mountain gaps, and some of 9th Corps reaches the north fork of the Rappahanock to sieze control of a bridge there.
Lee's letter to Jackson around this time tells him to march south, but is ambiguous; when Lee writes to the Confederate SecWar the next day however he is clearer that he meant for Jackson to move.


7th November:
loudoun_7th.jpg

The Union army is concentrating on Warrenton, and 9th Corps does the same thing it did earlier in the movement - secure the area on the far side of a bridge.
At this point McClellan is relieved in command, but his already-issued march orders are followed for the duration of the 8th and 9th.
(This is also around when the other half of Hood reaches Gordonsville.)
Lee's interpretation of McClellan's movements, to Stuart, is that it doesn't seem likely that McClellan will be trying to interpose between Jackson and Longstreet. He also says that if McClellan does push Lee back he'd have Longstreet fall back through Madison to make a junction with Jackson coming out of Swift Run Gap.
Jackson may at this point have ordered a concentration on Winchester to strike north (we mostly know that he cancelled the concentration overnight 9th-10th November)

8th November
loudoun_8th.jpg

6th Corps holds the Thoroughfare Gap area to shield Gainesville while 5th Corps goes through.
Lee is more explicit that Jackson must move now (he won't).
Walker has shifted to Madison Court House, possibly to defend the route by which Lee thinks he may have to retire.


9th November:
loudoun_9th.jpg

Much of the Army of the Potomac is now concentrated at Warrenton. 6th Corps leaves Thoroughfare Gap to 11th Corps (currently around Gainesville) and is under orders to move to Warrenton as well, but the change of command stops the army moving.
3rd Corps is also around Warrenton at this point - components of the corps have been seconded to 9th Corps or arriving by rail, but by now the whole corps is present (albeit spread out).



Interestingly, on this date (9th November), Lee told Stuart that there were dispatches to the effect that McClellan was concentrated "in the vicinity of Piedmont" (a theme he repeated to the Confederate SecWar on 10th November). This is a bit off...

scout_error.jpg

Later on the 10th Stuart discovered a division-plus of 9th Corps at Amissville.

loudoun_8th.jpg


loudoun_9th.jpg
 
Last edited:

Saphroneth

Major
Joined
Feb 18, 2017
Based on looking over the campaign map, the problem with a straight dash south is pretty much the positions of AP Hill and DH Hill.

If a single corps is moving south then it's vulnerable to AP Hill striking it in the flank or rear while DH Hill (+ Walker) is in the front. So you need a minimum of two corps striking south just by the time you reach DH Hill (one to face AP Hill and one to face DH Hill); if DH Hill is forced back behind the Blue Ridge then you start looking like you need a third corps, though conceivably both Ashby's and Snicker's gaps could be covered by elements of the same corps.

9th Corps is over the river on the 26th and 27th; 1st Corps doesn't cross until the 30th, but assuming that they could somehow cross on the 28th (no pause and a second bridge) then you have a column with 9th Corps leading and 1st Corps following. On the 28th it's got its leading corps around Waterford and Hillsborough, and on the 29th and 30th it could move further south enough to occupy Snickers Gap and the Philomont area.

Problem is, even in this ideal situation there's only two days for them to (1) repulse DH Hill such that he can't come in on the flank, and (2) move south past Warrenton and Waterloo VA. If they haven't reached Waterloo VA by the 1st then Pickett is in front of them and will beat them to Warrenton.
That's about 25+ miles, a distance Walker could only just manage over the same space of time when there was no battle to be fought.
 
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