If they will not meet us on the open sea (a Trent TL)

[Saphroneth]

Using Livermore, estimates of Confederate forces. I'll start with Present (the numbers from Livermore), and then try to strip down to PFD. These numbers are from April 1862, so before any of the big battles (for the most part).


The Army of Northern Virginia had 110,000, and in Western Virginia (including Jackson) there were about 20,000, along with 15,000 at and around Norfolk. This includes all the defensive forces in and around Richmond, and totals 145,000.

The Army of the Mississippi had 94,000, the Army of Eastern Tennessee had 16,000 and the Army of the West had 34,000. With Pillow's Brigade (3,800) and the troops from Forts Henry and Donelson (about 20,000) that means a total Present in the west of 170,000.

Trans-Mississippi there were about 13,000.

State forces and garrisons (NC, SC, Georgia, Missouri, Arkansas, Florida, Trans-Mississippi) totalled about 120,000, with probably some extras in Louisiana not accounted for here.


For want of any better data to use, I'll assume a discount for many of these forces along the same lines as that to convert Union Present to Union PFD (about 15%, a little larger than the proper discount to the Union). This puts the force in the Army of Northern Virginia as being about 93,500 PFD, which is pretty close to how it was in the Seven Days (once the 6,500 casualties from Seven Pines are removed and the reinforcements from elsewhere are added) with the balance being the result of sickness and desertion. As I'm measuring both sides as they were in early 1862 to get strengths, that's what I'll use.

By this metric the PFD in the west is about 144,000, split with roughly 110,000 east of the Mississippi (most of them in the Army of the Mississippi, historically, and includes the ex Army of Mobile and Army of Pensacola) and 34,000 west. Much of this is holding forts, but there's easily enough to form manoeuvre forces. (It also doesn't count Island Number Ten, with about 6,000)

In Indian Territory and New Mexico there's less than 10,000 PFD.



The coast dividend to be calculated here assumes that there's no troops from Louisiana (as they'd already joined by the time of the Present numbers I'm using to estimate) but that the NC, GA and AL troops are available - this totals about 46,000 PFD - and that the force in Norfolk is also available if need be, as Fort Monroe plus Norfolk put together can be defended by less than 15,000 troops.


Army of Northern Virginia 93,500 PFD
Jackson's Valley force 16,000 PFD plus Heth's detached brigade of 3,000 PFD
Reinforcements (from coasts) = 24,000 PFD (NC, GA)

Total force for campaign is about 135,000 PFD, so enough for three 45,000 PFD "corps" in the true sense of the word (functionally they'd be wings, with Johnston in overall command and under e.g. Longstreet/Smith/Lee). If Johnston gets wounded then Lee would take over and Jackson would have his wing.

15,000 troops as reserves (or garrison troops) in Peninsula and at Norfolk


Western theatre:

~40,000 PFD in forts, ensuring the Union cannot attack, partly balanced by 22,000 from coasts.
Smith, Polk, Bragg, Hardee each controlling a corps of average 33,000 PFD



So, overall situation:

Line of the Potomac
JE Johnston has 135,000 PFD against McClellan (with 33,000 in West Virginia incl. Harper's Ferry, 66,000 in Washington, 11,000 in Baltimore for a total of 110,000, plus some recruits but not many). Functionally this would mean McClellan having to withdraw to the line of the Potomac.


Along the Mississippi (AS Johnston OpCon)
Bragg has 33,000 PFD against Pope's 20,000
and Hardee has 33,000 PFD against Grant's 30,000

Eastern Tennessee/Kentucky area (Beauregard OpCon)
Polk and Smith each have 33,000 PFD against Buell's 40,000

Any of these corps could bring in up to a division from the forts if they really needed them, and it may be that instead Grant would end up facing two corps instead of one to defeat him in detail. It's quite possible the Union has to retreat mostly out of Kentucky and hold the Ohio.

 

[Sir Omega]

Broadly speaking I think the Union's going to have to stand on the defensive in the south - OTL they were quite sluggish about making offensives and the manpower assigned to go on the offensive was whatever could be spared once the needs of the defence were met.

But would they? I know that the conditions were different, but from what I remember the more prudent generals like McClellan were permanently cajoled by the president to move more aggressively. They may try to copy from Napoleon's strategy - attack one enemy aggressively, so as to defeat them in detail and not allow them to co-ordinate.

 

[Saphroneth]

But would they? I know that the conditions were different, but from what I remember the more prudent generals like McClellan were permanently cajoled by the president to move more aggressively.

Ah, now there's the rub- McClellan and others were cajoled to attack (preferably head on) rather than to merely move aggressively (which means manoeuvring the enemy out of positions). Lincoln had a vision of what an army looked like when it was aggressive, and it was slugging head on into enemy positions because that was supposedly better for the morale of the men.
It says a lot that Lincoln reacted to Fredericksburg favourably, as being the kind of thing the Army of the Potomac needed to do over and over.

But when it came to uncovering Washington, he could get spooked remarkably easily. The Confederates actually played him like a fiddle on this front, using Jackson's small force in manoeuvres explicitly intended to ensure that McDowell's corps would be kept back to help defend Washington (you know, along with the tens of thousands of other troops present) instead of reinforcing McClellan on the Chickahominy or the James. And while nobody's ever given a reason for why McClellan was relieved historically, the one which makes the least sense is a lack of aggression - at the time of his relief McClellan was charging down the Loudoun Valley, cutting off Jackson from Longstreet and getting in position to either strike Longstreet or push him back before shifting to cross the Rappahannock.
One plausible explanation, though, is that by moving so far south he'd apparently opened the way for Jackson to attack the capital (which was defended by merely an army larger than Jackson and Longstreet put together).

They may try to copy from Napoleon's strategy - attack one enemy aggressively, so as to defeat them in detail and not allow them to co-ordinate.

The problem, then, is how to conduct this theoretical attack. The campaign season doesn't start until March or April, by which point the British are a major problem and have been for months, but if McClellan tried going on the offensive directly down Virginia with eight divisions he'd end up in a horrible state. (It's actually impossible to attack Richmond over land on a timescale of less than months and without overwhelming numbers, because the blockade of the Union prevents any of the rivers being used as supply routes and so you have to repair the rail line as you go (as well as providing garrisons sufficient to protect the whole line, which let's not forget is a hundred miles long). OTL's Overland campaign relied on control of the rivers - bestowed by the Peninsular Campaign which is flat impossible TTL - to outflank the various good Confederate defensive positions, but a TTL offensive wouldn't be able to.

That would mean the attack would have to go from Washington to Gordonsville (pausing for some time to repair the rail lines) and defend against the possibility of an outflanking move via Manassas Gap railroad. It would then need to turn right at Gordonsville (guarding against the possibility of an attack from Charlottesville), and come down the rail line to Hanover Junction before turning south to Richmond.

If that rail line is cut anywhere along the length of it, the army starves until it surrenders. It simply does not have an alternative supply path.

So, assuming for a moment that you have the rail line garrisoned at about a division every thirty miles (pretty sparse against possible attacking columns of one two-division corps!) you have about four divisions occupied doing that. Now you're down to a manoeuvre force of perhaps five divisions (or four if both Washington and Baltimore are garrisoned against the British) and you're facing a Confederate force concentrated around Richmond of up to thirteen divisions.


Frankly, you're dead.



What the Union's actually doing TTL is trying to knock out the British quickly before going back to handling the South, but the problem is simply that there's not the resources to do much more than what I've shown - there's so little left once the issue of defence is handled.

 

[Sir Omega]

h, now there's the rub- McClellan and others were cajoled to attack (preferably head on) rather than to merely move aggressively (which means manoeuvring the enemy out of positions). Lincoln had a vision of what an army looked like when it was aggressive, and it was slugging head on into enemy positions because that was supposedly better for the morale of the men.

So pretty much Grant's 'tactics'. I presume that towards the end towards the end the difference in manpower and materiel were too much to overcome, because I sincerely think that any competent strategist should run rings, so to say, around somebody enacting this approach to warfare.

The problem, then, is how to conduct this theoretical attack.

Ah, I don't mean to say that it's a good idea militarily speaking, but that it may be forced upon the Armies by outside forces, like plummeting morale and lower support from civilians due to enemy encroachment and the like, creating the need for a major victory as soon as possible, political interference like changing the theater commander to another who's views are closer to the vision of the more... dilettante in military matters political leaders, and so on...

As a sidenote, the ACW Armies, both the North and the South, seem almost feudal at times, with people with no experience or training in warfare given ranks and positions of leadership thanks to the men they themselves recruited and equipped.

 

[Saphroneth]

So pretty much Grant's 'tactics'. I presume that towards the end towards the end the difference in manpower and materiel were too much to overcome, because I sincerely think that any competent strategist should run rings, so to say, around somebody enacting this approach to warfare.

A lot of it was that Grant had access to such a preponderance of manpower. McClellan OTL wanted to make a deep draft on the country's manpower straight off and win the war quickly, but that would be expensive!

Grant's problem, really, is that he was competent operationally but didn't have a strategy as such. He definitely tried to avoid battle on bad terms with the Army of Northern Virginia, so it wasn't just a case of trying to wear down the enemy in slugging matches - but I think he had to make the attacks or he'd be viewed as timid and replaced. It destroyed the offensive morale of the army, to the point that by Cold Harbor even the generals were saying in front of the men that the attacks were suicidal.

Ironically, after huge casualties and massive reinforcements, Grant ended up basically where McClellan (had he been given his head) would have ended up about early June 1862, and then proved unable to conduct regular approaches with any competence.

As a sidenote, the ACW Armies, both the North and the South, seem almost feudal at times, with people with no experience or training in warfare given ranks and positions of leadership thanks to the men they themselves recruited and equipped.

It makes purchase seem positively benign, yes. One of the ones that always amazes me is corps commanders - Lincoln signed several appointments for political favourites (e.g. Sumner) as Corps commanders, making them essentially invulnerable to being removed even for poor performance. There's a very strong argument that McClellan created the "wing" organization of his army specifically so he could put someone to outrank Sumner!

 

[Saphroneth]

So I got a second opinion on the Confederate ORBAT. Mixed bag on the results compared to my initial assessment, but the good news about the new version is that it's got divisions and brigades.


JE Johnston's Army of Northern Virginia (with Valley and Fredericksburg force) is

1st Division (MG GW Smith) with brigades of GT Anderson, Wilcox and Toombs
2nd Division (MG Longstreet) with brigades of AP Hill, DR Jones and Pickett
3rd Division (MG Holmes) with brigades of French, Fields and SR Anderson
4th Division (MG Jackson) with brigades of Garnett, Burke and Fulkerson
5th Division (MG Ewell) with brigades of Elzey, Trimble and Taylor
6th Division (MG DH Hill, promoted historically late March) with brigades of Griffith, Featherstone (ex- GB Anderson) and Walker
7th Division (BG Early) with brigades of Early, Rodes and Kershaw
8th Division (BG Whiting) with brigades of Whiting, Hood and Hampton

Army of the Peninsula can leave a brigade to occupy Fort Monroe after it falls, and become

9th Division (MG Magruder) with brigades of Rains, McLaws and Cobb

At Norfolk, Huger can detatch Blanchard to occupy the defences and become

10th Division (MG Huger) with brigades of Colston, Mahone and Armistead

North Carolina can produce a full division:

11th Division (BG JR Anderson) with brigades of Wise, JR Anderson and Branch

And can combine Ransom's brigade with two more from SC/Georgia:

12th Division (BG Ransom) with brigades of Ransom, Gregg and Lawton

Leave Gist's brigade at Charleston (meaning the total garrison of Georgia/SC is still over 10,000 plus Gist) and you can produce

13th Division (MG Pemberton) with brigades of Evans, Drayton and Mercer.


These average about 10,000 PFD (3,000 per brigade plus divisional troops) or a bit more, but I'll assume 10,000 man divisions. It makes full allowance for fort units (e.g. Heth's brigade is elsewhere) and allows Johnston to place 30,000 at Manassas as a screening force (probably under DH Hill?) and take the other 100,000 across the Potomac - probably to march on Baltimore, though I suspect they'd clear the Valley first. The critical question here is how much McClellan is allowed to uncover Washington, because if he has to leave 30,000 troops there to counter DH Hill he's left with 36,000 PFD as his manoeuvre element and that's very much not ideal!

Johnston liked two division corps, which results in an interesting situation for such a campaign - McClellan would outnumber any one corps but be outnumbered against two, let alone five. The question of what Lee does is an interesting one as he's senior to JE Johnston.



In the West, meanwhile, there's 34 infantry brigades under AS Johnston at about 3,000 effectives each. Functionally Beauregard would be running the actual army.

1st Corps - MG Polk
BG Clark - Clark, Stewart, Wharton
BG Cheatham - Donelson, Maney, Maxey
BG Johnson - Pillow, Floyd, Buckner
(~30,000 PFD)

2nd Corps - MG Bragg
BG Ruggles - P Anderson, Gibson, Pond
BG Withers - Gladden, Chalmer, JK Jackson
BG Breckinridge - Bowen, Traube, Statham
(~30,000 PFD)

3rd Corps - MG Hardee
BG Hindman - Liddel, Wood, Marmaduke, Trapier
BG Cleburne - Cleburne, Hawthorn, Gardner
(~23,000 PFD)

4th Corps - MG Van Dorn
BG Sam Jones - Little, Hebert, Green
BG Sterling Price - Hogg, Churchill, Rust
BG Maury - Moore, Dockery, Phifer
(~30,000 PFD)



My concept of operations here is that they'd "roll up" the Union armies west to east. To start with Dorn and Hardee would hold the frontier (along the Cumberland River) under Johnston, and Polk and Bragg would concentrate against Pope (under Beauregard), pretty much flattening him 3:1 unless he evacuates, before going after Grant. Once Grant's localized then Johnston (under Hardee and Van Dorn) can concentrate against Buell, probably forcing him to retreat in the direction of Louisville.


The grand total here of the field forces comes to about 233,000 PFD, and there's a lot of slack in the system. Another couple of divisions could be provided for either army without much strain (these counts do not include fort garrisons, for example there's 29 infantry regiments in the OTL garrison of Fort Donelson and only 16 are in the above ORBAT, and no coast dividend is represented), and of course by the time the campaign season opens (March-April) there's good weapons flooding into the Confederacy.
I think the likely outcome for the Union is that they suffer a nasty defeat or two and have to retreat from Kentucky and south Missouri. Worst case would be that Pope, Grant and Buell are all stomped on in succession and the Union has no good units to rely on in the West.



Honestly, though, I might kill one of the Johnstons just to make it easier to follow...

 

[nepcotevalley]

Should either A.P. Hill.. or D.H. Hill be worried ? Regards.

 

[Dathi THorfinnsson]

Hmmm...
I've got a couple of questions about the Confederates here. Sure, they don't need nearly as many coastal defense troops - but can they really move and supply the additional numbers? Especially inland?

Sure, they've got access to overseas supplies now, but getting everything in to inland battlefields is going to be ... tricky, I'd think.

Also, several of the Confederate generals were, afaik, almost useless as generals. Are they going to be able to USE these extra troops effectively?

Also, if the CSA DOES take KY back, there goes the Union's best hope for saltpetre (all those bat caves).

 

[Saphroneth]

I've got a couple of questions about the Confederates here. Sure, they don't need nearly as many coastal defense troops - but can they really move and supply the additional numbers? Especially inland?

Yes. The forces in the west are spread across hundreds of miles in width, and the forces in Virginia are not much larger than OTL (early) 1862. They have train routes, and indeed have the Rappahannock river for waterborne supply.

Also, several of the Confederate generals were, afaik, almost useless as generals. Are they going to be able to USE these extra troops effectively?

Probably. Beauregard is good and both Johnstons are serviceable, and the CSA actually tended to have better command at the brigade level which helps a bit. It's true there were some turkeys, but a lot of Union generals screwed up as well - in particular, IIRC every one of McClellan's corps commanders messed up at least once on the Peninsula.

There's only so much even a good general can do against 2:1 odds, especially if the other army is commanded by someone competent.

 

[The Gunslinger]

What's going to happen in Missouri? It seems to me that it see sawed towards whomever was winning (early for the Confederacy, later for the Union).

 

[Saphroneth]

The first version of the TL had the CSA get the section south of Cairo IL. I might revise that, depending on where the slave plantations were...

 

[The Gunslinger]

The first version of the TL had the CSA get the section south of Cairo IL. I might revise that, depending on where the slave plantations were...

The bulk of it is a broad swathe along the banks of the Missouri River. The southern portion appears to have very few slaves.

 

[The Gunslinger]

It's a little easier to see here, the number of slaves per capita was very low for most of the state, but it's kind of hard to tell with the groupings as big as they are.

 

[Saphroneth]

Hmmm. I don't doubt the CSA would love to have Kansas and Missouri, and southern IL for that matter, but they would probably not realistically get it.

Something to think about - maybe there's a good river line or something.

 

[EnglishCanuck]

Because why not here's a few ideas:

I've got a couple of questions about the Confederates here. Sure, they don't need nearly as many coastal defense troops - but can they really move and supply the additional numbers? Especially inland?

In Virginia this is less of a problem, but in Kentucky, Tennessee, and Missouri? More problematic since the Northern railroads are superior to those in even Kentucky, so getting armies larger than 40,000 plus moving swiftly will be difficult, but with all that space if you can concentrate men even briefly you get a nice advantage. However, AS Johnston would need to grow as a commander in order to use them effectively and stop trotting around like a glorified brigade commander, which was his biggest weakness/what got him killed at Shiloh.

So arguably in 1862 you'd see some sort of invasion of Kentucky to foil any Union attempts up the Mississippi, but you can't move more than 50,000 men easily in that terrain as Grant found out in his attempts at Vicksburg.

Sure, they've got access to overseas supplies now, but getting everything in to inland battlefields is going to be ... tricky, I'd think.

This is most tricky for the Western theater. As New Orleans doesn't fall right in the opening of 1862 then the CSA retains control of the mouth of the Mississippi, but at the same time the forces in the West are spread so far out that organizing and resupplying them will take months to even get them new weapons, so by and large they will be roughly the same until summer 1862, but will still be last to get new weapons and supplies from overseas. The rail routes aren't great, and everything must go upriver.

In the East OTOH they have access to a number of excellent ports and are much better connected via railroad, which means the Army of Virginia will be getting new weapons and supplies by at least spring 1862, giving them a huge morale and material boost. Anything captured from the Union in this period is just a plus. This will compound over time as the Union can only use what they capture, produce, or smuggle in degrading their overall effectiveness. However, this will be peak Confederate numbers as like OTL the smaller manpower pool of the South will dwindle over time, so they will try to strike decisive blows immediately.

Also, several of the Confederate generals were, afaik, almost useless as generals. Are they going to be able to USE these extra troops effectively?

In some cases, definitely not. However, Lee could probably perform some wondrous maneuvers with 130,000 men under his command, and God help the Army of the Potomac if he catches them with their pants down even once. However, in the West you have what can charitably be called a mixed bag of officers, so even the extra men wouldn't be that much of advantage, you've still got Polk, Beauregard, and Pemberton in important positions...

Also, if the CSA DOES take KY back, there goes the Union's best hope for saltpetre (all those bat caves).

There are other methods, but unlike the caves they will take 1+ years to develop or begin turning out anything resembling a good quantity of usable nitre.

 

[Saphroneth]

So arguably in 1862 you'd see some sort of invasion of Kentucky to foil any Union attempts up the Mississippi, but you can't move more than 50,000 men easily in that terrain as Grant found out in his attempts at Vicksburg.

Which is why they're spread out in four widely disparate corps and mostly on good communication lines (e.g. the Mississippi). The whole point of a corps is to be a force capable of independent movement, large enough to defend itself and small enough to fit down the roads, and TTL the Union doesn't really have the concentration of force to make it decisive.

This is most tricky for the Western theater. As New Orleans doesn't fall right in the opening of 1862 then the CSA retains control of the mouth of the Mississippi, but at the same time the forces in the West are spread so far out that organizing and resupplying them will take months to even get them new weapons, so by and large they will be roughly the same until summer 1862, but will still be last to get new weapons and supplies from overseas. The rail routes aren't great, and everything must go upriver.

Actually, they don't lose some of the important rail junctions so they're better off than OTL. The OTL penetration into Fort Henry cut off one of the two rail lines towards Bowling Green.

But the waterborne transport is the key, really, it's much more efficient than rail and transport in the period was pretty much "get it to the nearest river".

In the East OTOH they have access to a number of excellent ports and are much better connected via railroad, which means the Army of Virginia will be getting new weapons and supplies by at least spring 1862, giving them a huge morale and material boost. Anything captured from the Union in this period is just a plus. This will compound over time as the Union can only use what they capture, produce, or smuggle in degrading their overall effectiveness. However, this will be peak Confederate numbers as like OTL the smaller manpower pool of the South will dwindle over time, so they will try to strike decisive blows immediately.

One thing I'm not certain upon is whether the South would conscript. Certainly the two field armies totalling ~230,000 is quite small compared to the size of the Confederacy (though the number of men with the field armies is higher as there's also slaves and some free blacks, especially in the East, who don't fight but who do jobs that in the Union are done by soldiers).

Lee could probably perform some wondrous maneuvers with 130,000 men under his command, and God help the Army of the Potomac if he catches them with their pants down even once.

Funny thing is, it might be JE Johnston controlling them (though he too was quite a manoeuvrist). But Lee's superior, so if he's with the Eastern army he's in command.

However, AS Johnston would need to grow as a commander in order to use them effectively and stop trotting around like a glorified brigade commander, which was his biggest weakness/what got him killed at Shiloh.

The concept of operations means that to some extent he has Beauregard to lean on, plus Lee if he's with the West. (Not decided yet where Lee goes, he's junior to AS Johnston but that's about it). ASJ as the theater commander with Beauregard and Lee as army commanders, each with two corps? Possible...

 

[EnglishCanuck]

Which is why they're spread out in four widely disparate corps and mostly on good communication lines (e.g. the Mississippi). The whole point of a corps is to be a force capable of independent movement, large enough to defend itself and small enough to fit down the roads, and TTL the Union doesn't really have the concentration of force to make it decisive.

Depends on where they concentrate. If the February offensives against Donelson and Henry are cancelled then the CSA is up and the Union is stronger in Kentucky, but they could probably concentrate enough force to spar around Island No. 10 for a while, if only to pin Beauregard down while the two sides fumble about in Kentucky which will be more of a Confederate priority if Nashville is secure.

Actually, they don't lose some of the important rail junctions so they're better off than OTL. The OTL penetration into Fort Henry cut off one of the two rail lines towards Bowling Green.

But the waterborne transport is the key, really, it's much more efficient than rail and transport in the period was pretty much "get it to the nearest river".

The rail network was still iffy when contrasted with its Union counterpart, but retaining control of the Mississippi will be the big thing giving the Confederates a natural highway to move goods up the river from New Orleans. So that's a plus, but getting things from the ports to the armies so far apart in the West will be a more time consuming process than in the East where they are right next to the sea.

One thing I'm not certain upon is whether the South would conscript. Certainly the two field armies totalling ~230,000 is quite small compared to the size of the Confederacy (though the number of men with the field armies is higher as there's also slaves and some free blacks, especially in the East, who don't fight but who do jobs that in the Union are done by soldiers).

It's an open question, but most likely they conscript by 1863 since any envisioned offensives will be costly and they just won't have the volunteers to make up for battle losses. I think each side would run into that problem by the next campaigning season so it's more likely than not if the war drags on.

Funny thing is, it might be JE Johnston controlling them (though he too was quite a manoeuvrist). But Lee's superior, so if he's with the Eastern army he's in command.

JE Johnston's relationship with Davis will poison that well, so there's going to be a problem in the East as the two humbug each other, and if Johnston does what he did in the Peninsula then Davis might sack him and replace him with Lee should his patience fade.

The concept of operations means that to some extent he has Beauregard to lean on, plus Lee if he's with the West. (Not decided yet where Lee goes, he's junior to AS Johnston but that's about it). ASJ as the theater commander with Beauregard and Lee as army commanders, each with two corps? Possible...

Lee would be interesting in the West. He'd certainly be capable of getting the chaff transfered since he has Davis's confidence, and he could probably whip the army into shape better than Bragg or Johnston managed through 62-64, but at what cost in offensive action?

 

[Saphroneth]

Johnston specified he'd need 13 divisions to invade the North, and he's got them. The main question is how he'd do it.

My guess is that he'd put 30K at Manassas as a covering force to threaten Washington, then move up both sides of the Blue Ridge and go after the Federal forces in and around the Valley. With ten divisions against the Federal three (assuming that Rosecrans and Cox are pulled back into the valley instead of being in OTL West Virginia), it's hard to see him failing, and Harpers Ferry is either being abandoned or captured.

Then it's crossing into Maryland and going after Baltimore, while having the covering force to discourage the Union sending their entire army to stop him. This is where it gets a bit interesting, as if the British have punched out Fort McHenry then the CSA could actually start using waterborne supply around Baltimore, take it from the Union, and then Washington is cut off.

I think.

 

[Saphroneth]

Hm, staring at a very large map of Maryland for several minutes has revealed a possible campaign plan.

It looks like there's a somewhat curving route around Washington at some remove (about thirty miles away) that stays away from the forts. It's about sixty miles long, which is about four days of marching given the need to stay with the wagon trains, and it looks like it has two parallel roads for most of it (which would mean that two corps could advance side by side, functionally creating the "box" formation of moving corps that allows two others to pile in on short notice if one is attacked. It's also hard to block because the blocking force would need to spread itself to block both roads and avoid a gap between (specifically, usually about ten miles) and with the small corps favoured by JE Johnston the columns wouldn't be too long with two corps in succession on the same roads.

This route terminates pretty much at and around Baltimore (held by a 1 division garrison) and if McClellan sends his entire force out of Washington then he might be able to defend Baltimore long-term but he'd lose Washington so it'd be kind of pointless. He'd need to leave at least two divisions in Washington, and that would leave the odds for a battle being - at best - 80K Confederates vs 55K Federals.

Thing is, I'm not sure this could be supplied. It could definitely make the move (armies could travel for several days as a flying column, about ~8 IIRC) but then bringing more supplies in is difficult and would functionally require a friendly population.

The alternative #1 is that JE Johnston pretty much sets up shop on the north bank of the Potomac, robustly protects his supply route with some of his large force, and commences regular approaches. The DC fort ring is at this date somewhat finished, but it might be weaker than OTL because of the needs of the coastal forts - and, as in the first version, the Rockville Turnpike is actually not properly covered.

Alternative #2 is that the Confederacy does launch the Baltimore operation, and uses Virginia as the escort for landing supplies somewhere near Baltimore. Very risky.

Alternative #3 is to basically ignore Washington for now and go up and raid Pennsylvania with eight divisions, leaving five back around Washington as a threat to prevent the Union sending much forces out.

There's others too. The main question is, which one appeals most to the manoeuvrist that is JE Johnston...

 

[The Gunslinger]

Hmmm. I don't doubt the CSA would love to have Kansas and Missouri, and southern IL for that matter, but they would probably not realistically get it.

Something to think about - maybe there's a good river line or something.

Sadly, the only good river is the Missouri River that cuts through the center of the state, and that puts Saint Louis and just about everything worth having in Confederate hands and leaves many slaves and slave owners in Union Missouri.

Kentucky is more important for both sides, but Missouri could end up being a thorn in the Union's side if the Confederacy can manage to wage a small campaign there.

But it looks like an all or nothing state and a plebiscite might be best in all honesty.