McClellan What Would McClellan Have Done?

[Saphroneth]

As for what Lee said:

He's talking about passing Yorktown or the James batteries by water. He talks about a landing behind Magruder's line - "effecting a landing in your rear above your lines at Yorktown and Williamsburg".

He is completely focused on the idea of McClellan landing behind Magruder, but he doesn't even mention a breakthough on land - from the beginning of the letter to the end, he is entirely focused on Union forces arriving in the rear by water. He even mentions Magruder taking action to delay the Union forces as they move inland, and destroying the landings which they could use to do this.

Red: passing batteries
Blue: Union landings in the rear of the Confederate force


Everything else in the letter is about how Lee is advising Magruder to keep his line of retreat open in the event this happens. There's no mention of a breakthrough on land - if Lee wanted Magruder to retreat with his whole force in the event of a breakthrough on land he would have to say so separately, since Magruder certainly had an avowed intent after Lee's first message to continue to garrison Yorktown in the event of a breakthrough.

Given this order from Lee, in the event of a land breakthrough by McClellan, Magruder would most effectively comply with Lee's intent by keeping the York closed so that Magruder could successfully retreat without McClellan landing troops behind him. For Magruder to abandon Yorktown and thus open the York would make Lee's worry happen.

 

[67th Tigers]

Sorry, I want to check your maths here.


snip

Total: 3,337 effectives.

If you think McClellan had between 133,000 and 167,000 effectives with his army... that might explain some confusion?

Indeed. 3,500 (say) effectives could have held Yorktown against any assault. The walls were thick, and they had a lot of artillery. The only option would have been to reduce it first, and then assault the breach if they refused to surrender. It'd be something like Badajoz.

Assaulting without reduction? That's a fancy way of giving the defenders target practice...

 

[DanSBHawk]

Sorry, I want to check your maths here.



The garrison of Yorktown proper is the 13th Alabama, 6th & 23rd Georgia and some heavy artillery.

In addition, Magruder explicitly named the 26th AL and 46th VA as units he would add to the garrison if they had to fall back. That's as of April 7; note that the 26th AL actually did join the garrison by late April.


Late April effective strengths:

46th Virginia: 356
Other units of infantry: 1,830 (all were in the garrison at that time)
Artillery: 1,151 (in nineteen heavy batteries)
View attachment 502771
View attachment 502772
Total: 3,337 effectives.

If you think McClellan had between 133,000 and 167,000 effectives with his army... that might explain some confusion?

How many men would Lee be willing to sacrifice leaving behind at Yorktown?

 

[Saphroneth]

How many men would Lee be willing to sacrifice leaving behind at Yorktown?

Well, given that he can always evacuate them by boat up the York overnight at the point when the siege works are nearly complete, he's not really sacrificing them! The only way they'd be lost is an assault taking the position without siege prep, which is a recipe for massive Union casualties and probably a net gain (counting both the time and the Union casualties).

 

[DanSBHawk]

As for what Lee said:

View attachment 502770

He's talking about passing Yorktown or the James batteries by water. He talks about a landing behind Magruder's line - "effecting a landing in your rear above your lines at Yorktown and Williamsburg".

He is completely focused on the idea of McClellan landing behind Magruder, but he doesn't even mention a breakthough on land - from the beginning of the letter to the end, he is entirely focused on Union forces arriving in the rear by water. He even mentions Magruder taking action to delay the Union forces as they move inland, and destroying the landings which they could use to do this.

Red: passing batteries
Blue: Union landings in the rear of the Confederate force


Everything else in the letter is about how Lee is advising Magruder to keep his line of retreat open in the event this happens. There's no mention of a breakthrough on land - if Lee wanted Magruder to retreat with his whole force in the event of a breakthrough on land he would have to say so separately, since Magruder certainly had an avowed intent after Lee's first message to continue to garrison Yorktown in the event of a breakthrough.

Given this order from Lee, in the event of a land breakthrough by McClellan, Magruder would most effectively comply with Lee's intent by keeping the York closed so that Magruder could successfully retreat without McClellan landing troops behind him. For Magruder to abandon Yorktown and thus open the York would make Lee's worry happen.

How is it in any way different if McClellan gets above Magruder and cuts him off on the peninsula by land or by water?

 

[Saphroneth]

How is it in any way different if McClellan gets above Magruder and cuts him off on the peninsula by land or by water?

It's completely different, because one of them is cutting off Magruder's whole army in such a way that McClellan already has control of the York - so holding Yorktown is pointless - and the other is cutting off a small part of Magruder's force in such a way that holding Yorktown (and thus controlling the York) helps him evacuate the rest.

 

[DanSBHawk]

Well, given that he can always evacuate them by boat up the York overnight at the point when the siege works are nearly complete, he's not really sacrificing them! The only way they'd be lost is an assault taking the position without siege prep, which is a recipe for massive Union casualties and probably a net gain (counting both the time and the Union casualties).

That's ridiculous. If McClellan gets above Yorktown on the peninsula, then all it takes is one gunboat running by Yorktown at night and the confederates no longer control the York.

 

[67th Tigers]

That's ridiculous. If McClellan gets above Yorktown on the peninsula, then all it takes is one gunboat running by Yorktown at night and the confederates no longer control the York.

That is ridiculous. How does one gunboat running past mean that supply ships can steam up the river and supply an army above it?

 

[DanSBHawk]

That is ridiculous. How does one gunboat running past mean that supply ships can steam up the river and supply an army above it?

McClellan can't advance without supply ships?

If McClellan gets above Yorktown on the land side, and the navy gets above Yorktown on the river, then that is exactly what Lee was warning about happening. Any confederate troops still on the peninsula get cut off from retreating.

You two are simply making excuses for McClellan acting timidly.

 

[67th Tigers]

McClellan can't advance without supply ships?

If he has an aversion to his army starving...

 

[DanSBHawk]

If he has an aversion to his army starving...

Good thing he didn't attempt an overland campaign.

 

[Saphroneth]

Lee is explicitly worried about a landing in Magruder's rear. If I may:

This is the situation at the start, in terms of Magruder's defences. Please excuse the map's inaccuracies with regard to the specifics like the course of the Warwick, it's a basemap which shows the area at scale and that's the thing I actually need here.


In the event of a land breakthrough:

The Confederates still control the York, because the Union can't pass the batteries effectively. Nothing has changed about the situation on the York river itself.
The Confederates can either retreat north and hold the Williamsburg position (which is something Lee specifically mentions as a possibility even if the Warwick position is abandoned), or retreat all the way to the Chickahominy, but the Union can't supply their forces far enough north to follow. This is a function of how hard it is to move supplies over the roads - you need your supply base nearby in land terms because wagons are slow.

Confederate troops can retire north as a response to the breakthrough, and (depending on where it is) Union forces are unlikely to be able to cut off the majority of them. In many cases a breakthrough simply won't permit large amounts of troops to be crossed quickly and in good fighting order (Lee's Mill bridge being one exception, the Redoubts being the other - anywhere else it's passing troops over a dam or through a river, not using a road).

If any troops cut off are in excess of those needed to defend Yorktown, they can be moved out by boat up the York.



If the Union can pass the batteries effectively with the Warwick line still garrisoned, then this is what Lee is describing as his worry:

This is the enemy passing the river batteries and landing troops. Note that once the Union is on the York they can land behind the Williamsburg line as easily as they can land in front of it; the only way Lee's comments about holding the Williamsburg line make sense is if the Union isn't on the York.

If the Union can effectively pass the batteries on the York, then - yes, they can outflank and render useless both defensive lines. If the Confederates abandon Yorktown, they are letting this happen, and this is why they would not do so unless forced to.


This is also why Lee mentions the possibility of falling back across the lower Chickahominy if the Union gets onto the York.



The reason I want to make this point is that:

1) If the Union cannot supply up the York (moving supply ships) then they cannot move the Union army close to Richmond. Strategic consumption prevents it.

2) If the Union cannot move troops up the York (moving troop ships to make a landing) then they cannot outflank the Williamsburg line, and this line is an effective defence.

3) If the Union can move troops up the York, then they can move their army by water to cut Magruder off - unless he abandons the Warwick line and retreats, probably over the lower Chickahominy.

4) If the Union can move supplies up the York, then they can march their army as far as the upper Chickahominy, and take control of the Richmond and York Railroad, thus letting them take up basically McClellan's initial siege positions. The only thing that prevents this happening basically instantly is marching time.



So, if McClellan breaks through the Warwick line on land and cuts Yorktown off, with a garrison of at least a few thousand troops, Lee has these options to consider.


1) Continue to supply Yorktown, evacuating the excess troops in the garrison not required to hold the walls; abandon the fort at a point when the Union's siege works are well advanced and they're ready to open fire.

In this case, the Union cannot start moving up the York until about the historical time.

2) Abandon Yorktown, evacuating the whole garrison by sea.

In this case, the Union can start moving up the York more or less immediately. This accelerates the timeline.


On the other hand, if Lee has the Warwick line abandoned entirely, then the Union can start moving up the York more or less immediately. This accelerates the timeline.



Note that if the Union tries taking Yorktown by storm without preparatory bombardment, that would also accelerate the timeline - but it's a recipe for simply hideous casualties. There's a reason why bastion forts assaulted frontally exacted huge tolls in blood from the attackers, and often held out - it's literally most of what they were for.



Now, up until this point I've been assuming that Yorktown closes the York to ships - and evaluating why Lee would be worried about the strategic consequences if it didn't.

But what if it didn't? What if navy ships can pass Yorktown and get into the York, even with Yorktown still garrisoned?

Well, if they can do it in this situation:

Then they can do it in this situation:

And the whole of the Warwick line could have been bypassed to exactly the same extent without any need for a costly breakthrough attempt on land.

 

[DanSBHawk]

Lee is explicitly worried about a landing in Magruder's rear. If I may:

View attachment 502793

This is the situation at the start, in terms of Magruder's defences. Please excuse the map's inaccuracies with regard to the specifics like the course of the Warwick, it's a basemap which shows the area at scale and that's the thing I actually need here.


In the event of a land breakthrough:

View attachment 502794

The Confederates still control the York, because the Union can't pass the batteries effectively. Nothing has changed about the situation on the York river itself.
The Confederates can either retreat north and hold the Williamsburg position (which is something Lee specifically mentions as a possibility even if the Warwick position is abandoned), or retreat all the way to the Chickahominy, but the Union can't supply their forces far enough north to follow. This is a function of how hard it is to move supplies over the roads - you need your supply base nearby in land terms because wagons are slow.

Confederate troops can retire north as a response to the breakthrough, and (depending on where it is) Union forces are unlikely to be able to cut off the majority of them. In many cases a breakthrough simply won't permit large amounts of troops to be crossed quickly and in good fighting order (Lee's Mill bridge being one exception, the Redoubts being the other - anywhere else it's passing troops over a dam or through a river, not using a road).

If any troops cut off are in excess of those needed to defend Yorktown, they can be moved out by boat up the York.



If the Union can pass the batteries effectively with the Warwick line still garrisoned, then this is what Lee is describing as his worry:

View attachment 502795

This is the enemy passing the river batteries and landing troops. Note that once the Union is on the York they can land behind the Williamsburg line as easily as they can land in front of it; the only way Lee's comments about holding the Williamsburg line make sense is if the Union isn't on the York.

If the Union can effectively pass the batteries on the York, then - yes, they can outflank and render useless both defensive lines. If the Confederates abandon Yorktown, they are letting this happen, and this is why they would not do so unless forced to.


This is also why Lee mentions the possibility of falling back across the lower Chickahominy if the Union gets onto the York.



The reason I want to make this point is that:

1) If the Union cannot supply up the York (moving supply ships) then they cannot move the Union army close to Richmond. Strategic consumption prevents it.

2) If the Union cannot move troops up the York (moving troop ships to make a landing) then they cannot outflank the Williamsburg line, and this line is an effective defence.

3) If the Union can move troops up the York, then they can move their army by water to cut Magruder off - unless he abandons the Warwick line and retreats, probably over the lower Chickahominy.

4) If the Union can move supplies up the York, then they can march their army as far as the upper Chickahominy, and take control of the Richmond and York Railroad, thus letting them take up basically McClellan's initial siege positions. The only thing that prevents this happening basically instantly is marching time.



So, if McClellan breaks through the Warwick line on land and cuts Yorktown off, with a garrison of at least a few thousand troops, Lee has these options to consider.


1) Continue to supply Yorktown, evacuating the excess troops in the garrison not required to hold the walls; abandon the fort at a point when the Union's siege works are well advanced and they're ready to open fire.

In this case, the Union cannot start moving up the York until about the historical time.

2) Abandon Yorktown, evacuating the whole garrison by sea.

In this case, the Union can start moving up the York more or less immediately. This accelerates the timeline.


On the other hand, if Lee has the Warwick line abandoned entirely, then the Union can start moving up the York more or less immediately. This accelerates the timeline.



Note that if the Union tries taking Yorktown by storm without preparatory bombardment, that would also accelerate the timeline - but it's a recipe for simply hideous casualties. There's a reason why bastion forts assaulted frontally exacted huge tolls in blood from the attackers, and often held out - it's literally most of what they were for.



Now, up until this point I've been assuming that Yorktown closes the York to ships - and evaluating why Lee would be worried about the strategic consequences if it didn't.

But what if it didn't? What if navy ships can pass Yorktown and get into the York, even with Yorktown still garrisoned?

Well, if they can do it in this situation:

View attachment 502799


Then they can do it in this situation:

View attachment 502798


And the whole of the Warwick line could have been bypassed to exactly the same extent without any need for a costly breakthrough attempt on land.

What Lee is warning about is the possibility of the confederates getting cutoff and unable to retreat off of the peninsula.

That's going to happen if the navy gets past and lands troops above Yorktown. And it's going to happen if the army gets past Yorktown on it's own, and the navy gets past Yorktown on it's own. It's the same exact situation. Confederate troops are cut off from retreating.

At no point in the letter does Lee stress a need to hold onto Yorktown and control the York River. The entire focus of his letter is to avoid a scenario where the confederate army gets trapped on the Peninsula. Lee is focused on the future battles against McClellan, not on desperately maintaining control of the York.

There is nothing from either Lee or Magruder that explicitly lays out a plan to keep Yorktown occupied after it becomes invested. The Magruder order does not go into any detail about long range plan concerning Yorktown. No explanations or contingencies or troop numbers about holding on to an invested Yorktown.

The notion that Lee would sacrifice valuable men in a doomed attempt to hold Yorktown is just a very unlikely fantasy scenario. It's far more likely that Lee would pull all the forces off of the Peninsula and then confront McClellan with as large of an army as possible.

 

[Saphroneth]

That's going to happen if the navy gets past and lands troops above Yorktown. And it's going to happen if the army gets past Yorktown on it's own, and the navy gets past Yorktown on it's own. It's the same exact situation. Confederate troops are cut off from retreating.

No, if the army gets through the Warwick line on its own, that won't happen - because the enemy can retire at the same marching rate as the Union can advance, once in clear terrain, and for almost all possible breakthrough points the Union won't be able to deploy their whole force as soon as they achieve a breakthrough.

That's why Lee keeps stressing landings, landings, landings. Forcing a passage of the batteries, effecting a landing in your rear, movements of the enemy by water, passing your lower river batteries, landing troops.

The Confederates can stay ahead of an enemy force advancing by land, especially since the Union can't march far before they have to draw rein for supply purposes. They can't outmarch troopships.

At no point in the letter does Lee stress a need to hold onto Yorktown and control the York River. The entire focus of his letter is to avoid a scenario where the confederate army gets trapped on the Peninsula. Lee is focused on the future battles against McClellan, not on desperately maintaining control of the York.

But the surest way to prevent a retreating Confederate army from being cut off is to control the York river until the main body of the army has retreated past Eltham's Landing.

There is nothing from either Lee or Magruder that explicitly lays out a plan to keep Yorktown occupied after it becomes invested. The Magruder order does not go into any detail about long range plan concerning Yorktown. No explanations or contingencies or troop numbers about holding on to an invested Yorktown.

Magruder explicitly laid out the need to send troops into Yorktown if they had to retreat:

under any circumstances. Twice.

Do you really think that Magruder couldn't imagine a situation where they were forced to retire and Yorktown ended up invested? If they have to retreat but Yorktown is still defended, there is no other possibility, unless McClellan just outright ignores Yorktown - but he can't.

The notion that Lee would sacrifice valuable men in a doomed attempt to hold Yorktown is just a very unlikely fantasy scenario. It's far more likely that Lee would pull all the forces off of the Peninsula and then confront McClellan with as large of an army as possible.

I really don't think you're following the argument here - the argument is that:
1) The time taken to reduce Yorktown is time that the Union cannot effectively advance, and is time Lee can use to concentrate more troops at Richmond. Trading 3,000 effectives for the safe retirement of the rest of Magruder's army is probably worth it by itself, and
2) Unless the Union is able to cut Yorktown off by running the batteries on the York, then he's not even sacrificing the men. They can be evacuated safely on any given night by boat.


So here's the question.

If Lee decided to hold Yorktown until siege works were well advanced, what advantages would it give the Union? Since you are claiming that Lee wouldn't do it because it's "a very unlikely fantasy scenario", what benefits does it give the Union to do this? And what are the costs to the Union?

Furthermore, if it's "silly" to besiege Yorktown in that scenario, what is the alternative way of getting past it?




Forts being used as delaying instruments to deny control of a logistic supply route to the enemy is basically the entire point of forts. It's the whole reason why they're built, except for where they're built close around or surrounding important locations (such as the fort ring around Washington, for example).

Look at Fort Montgomery at Rouse's Point, that's to control the Richelieu river's connection with Lake Champlain. Look at Fort Ticonderoga, it does the same thing.

 

[Saphroneth]

To frame it a different way.


Let's say that on April 6, McClellan forces the Warwick line by means of an attack at, oh, Wynn's Mill. Most of the Confederate force as-yet in the Warwick line pulls back on their right flank, then marches north to the Williamsburg line where they consolidate before either retiring to Richmond or holding the Williamsburg line.
For these purposes I will assume McClellan has a sea landing force available, as that's what Lee is worried about.


If the Confederates have abandoned Yorktown:

McClellan can ship troops up the York pretty much immediately, landing a division at Eltham's Landing and reinforcing it while the rest of his force follows up the Peninsula, able to operate off supplies landed from the rivers. This offers a good chance of cutting off most of Magruder's force and causing the surrender of a lot of Confederates. He can then advance towards Richmond pretty much as fast as his army can march.

If the Confederates have not abandoned Yorktown:

McClellan can follow the Confederates up the Peninsula until he is out of supply range of his current supply landings, which is not very far. He has no chance of cutting off most of Magruder's force and causing the surrender of a lot of Confederates, and he is unable to advance towards Richmond because his army is unable to sustain itself by wagon remotely that far from his current supply landings. He may even be stopped at the Williamsburg line, since he has no way to bypass it as he historically did.

The only way for McClellan to resolve this is for Yorktown to be unable to block supply or troop movement up the York. This means McClellan has to take Yorktown.


If Yorktown is defended:

McClellan can assault Yorktown, without siege prep. This is costly to his army (because it's an attack on an undamaged bastion fort) and is unlikely to work; it is an excellent way for a small force of Confederates to successfully hold off a much larger Union force and inflict significant casualties on them. That's the point of the walls, bastions, artillery and garrison.

McClellan can do siege preparations, and then assault Yorktown. If there are Union warships in the upper York then the garrison cannot evacuate, and are lost, but the siege preparations have taken up time - time which lets the Confederates muster forces at Richmond.

If there are not Union warships in the upper York, then the Confederates can evacuate their garrison when the siege prep is almost complete. They have gained very nearly as much time, but haven't lost any men.


Alternatively, McClellan can try and starve Yorktown out. This requires being able to interdict Confederate supply down the York, as otherwise Yorktown can simply be resupplied indefinitely down the York; once the York is interdicted, this means waiting. The garrison is captured in this case, but as noted it requires the Union being able to interdict Confederate supply down the York.






Basically, there is no way to quickly get the Union army close to Richmond unless either they take the heavy casualties required for a human-wave assault to overcome an undamaged bastion fort, or the Confederates simply abandon Yorktown without even trying to delay them there. The Confederates doing the latter would speed up Union operations so much that I have a hard time seeing why the Confederates would ever do it - it practically requires the Confederates to be helping the Union speed things up.

 

[DanSBHawk]

To frame it a different way.


Let's say that on April 6, McClellan forces the Warwick line by means of an attack at, oh, Wynn's Mill. Most of the Confederate force as-yet in the Warwick line pulls back on their right flank, then marches north to the Williamsburg line where they consolidate before either retiring to Richmond or holding the Williamsburg line.
For these purposes I will assume McClellan has a sea landing force available, as that's what Lee is worried about.


If the Confederates have abandoned Yorktown:

McClellan can ship troops up the York pretty much immediately, landing a division at Eltham's Landing and reinforcing it while the rest of his force follows up the Peninsula, able to operate off supplies landed from the rivers. This offers a good chance of cutting off most of Magruder's force and causing the surrender of a lot of Confederates. He can then advance towards Richmond pretty much as fast as his army can march.

If the Confederates have not abandoned Yorktown:

McClellan can follow the Confederates up the Peninsula until he is out of supply range of his current supply landings, which is not very far. He has no chance of cutting off most of Magruder's force and causing the surrender of a lot of Confederates, and he is unable to advance towards Richmond because his army is unable to sustain itself by wagon remotely that far from his current supply landings. He may even be stopped at the Williamsburg line, since he has no way to bypass it as he historically did.

The only way for McClellan to resolve this is for Yorktown to be unable to block supply or troop movement up the York. This means McClellan has to take Yorktown.


If Yorktown is defended:

McClellan can assault Yorktown, without siege prep. This is costly to his army (because it's an attack on an undamaged bastion fort) and is unlikely to work; it is an excellent way for a small force of Confederates to successfully hold off a much larger Union force and inflict significant casualties on them. That's the point of the walls, bastions, artillery and garrison.

McClellan can do siege preparations, and then assault Yorktown. If there are Union warships in the upper York then the garrison cannot evacuate, and are lost, but the siege preparations have taken up time - time which lets the Confederates muster forces at Richmond.

If there are not Union warships in the upper York, then the Confederates can evacuate their garrison when the siege prep is almost complete. They have gained very nearly as much time, but haven't lost any men.


Alternatively, McClellan can try and starve Yorktown out. This requires being able to interdict Confederate supply down the York, as otherwise Yorktown can simply be resupplied indefinitely down the York; once the York is interdicted, this means waiting. The garrison is captured in this case, but as noted it requires the Union being able to interdict Confederate supply down the York.






Basically, there is no way to quickly get the Union army close to Richmond unless either they take the heavy casualties required for a human-wave assault to overcome an undamaged bastion fort, or the Confederates simply abandon Yorktown without even trying to delay them there. The Confederates doing the latter would speed up Union operations so much that I have a hard time seeing why the Confederates would ever do it - it practically requires the Confederates to be helping the Union speed things up.

At no point does Lee say anything about continuing to hold Yorktown. In fact, he tells Magruder to destroy the wharves before he abandons the peninsula.

Magruder's message does not describe what would happen in the event of the army leaving the peninsula. His order may be part of an evacuation plan.

Simply show me anything from the confederate side that explicitly says that a garrison will be left at Yorktown if the army retreats from the Peninsula.

 

[Saphroneth]

Simply show me anything from the confederate side that explicitly says that a garrison will be left at Yorktown if the army retreats from the Peninsula.

...seriously? Magruder orders at least two regiments into Yorktown - he specifies two regiments he would like it to be, but he says that if those two can't go in two others will have to. He also specifies that they are to be added to the garrison if we fall back.

"re-enforced under any circumstances"
"at least two regiments"
"thrown into the garrison"
"two regiments under any circumstances must be added to the garrison"

If you have Magruder issuing an order to add two regiments to the garrison if they have to fall back, surely that's sufficient that they'll be leaving a garrison if they have to fall back?


(note that Magruder is not necessarily contemplating leaving the whole Peninsula here, but could retire to the Williamsburg line.)

 

[DanSBHawk]

If you have Magruder issuing an order to add two regiments to the garrison if they have to fall back, surely that's sufficient that they'll be leaving a garrison if they have to fall back?

(note that Magruder is not necessarily contemplating leaving the whole Peninsula here, but could retire to the Williamsburg line.)

Right. He's not necessarily talking about falling back from the Peninsula. He's not necessarily talking about falling back to Williamsburg. Later in April Magruder suggested moving the Warwick section of the line back to Blow's Mill. So Magruder's April 8th message does not explicitly say that Yorktown will be held even to the point that it is completely invested.

 

[67th Tigers]

Good thing he didn't attempt an overland campaign.

Indeed, since Grant's overland campaign depended upon seaborne supplies, including from West Point on the York. Without McClellan occupying the Peninsula, Grant's overland movement would have been impossible.

 

[Saphroneth]

Right. He's not necessarily talking about falling back from the Peninsula. He's not necessarily talking about falling back to Williamsburg. Later in April Magruder suggested moving the Warwick section of the line back to Blow's Mill. So Magruder's April 8th message does not explicitly say that Yorktown will be held even to the point that it is completely invested.

But Magruder says that it's to happen under any circumstances. And he says if we are forced to retire.

So if McClellan breaks through, that is a circumstance under which Magruder's army is forced to retire. And that circumstance is one in which Magruder adds two regiments to the Yorktown garrison.


Now.

What benefit does it give Magruder to then pull out of the Yorktown garrison? Because it benefits McClellan quite significantly for Magruder to pull out of the Yorktown garrison, because it gives McClellan almost a month and lets him set up his forward positions and supply base around Eltham's Landing within about two days of Yorktown being abandoned. From Yorktown being abandoned to McClellan reaching Bottom's Bridge, with the historical weather, is a bit less than two weeks.

Would Magruder rather McClellan reach Bottom's Bridge on May 17 (historical date) or April 20 (two weeks after a breakthrough on April 6)?