Could The Union Have Won Second Manassas?

[Josh The Lighthouse Guy]

Pope makes two major mistakes at Second Manassas.

1. Union attacks over a day and a half are uncoordinated. He squandered his numerical superiority over Jackson. The Confederate line was good but by no means unbreakable as the Union attacks came close at least once to piercing the line - close enough for some of Stonewall's men to literally throw rocks at the Yankees.

2. Pope has one of the worst cases of tunnel vision in military history. He is completely focused on attacking Jackson and dismissive of Longstreet's potential arrival.

Let us do a little armchair generaling. This isn't really a What If, but more a What Should Have Been.

If Pope successfully coordinates a large attack on the afternoon of Aug 29, what is the best part of Jackson's line to make and exploit a breakthrough?

Can Pope launch a dawn attack on Aug 30 anywhere with any chance of success, or does Longstreet's attack ensure even an optimal attack is rendered irrelevant by the end of the day?

If Pope recognizes Longstreet's arrival on Aug 29 - perhaps McDowell visits Porter, recognizes the threat, and persuades Pope it is a serious threat - what is the best course of action for the Union Army? Do they need to withdrawal across Bull Run during the night? Should Porter remain where he is off Longstreet's right flank and the rest of the Army shift southward to form a line connected to Porter?

 

[Noonanda]

So there were a couple breakthroughs on the 29th, the main one was under Hookers Division almost in the Center of the Line. If that Attack had actually been supported, the Battle may have gone differently. Same with the attack on Hills Division on the Confederate Left.

 

[repman66]

Pope needs to pin Jackson and allow the army of the potomac to arrive -- 2nd and 6th corps on the battlefield, attack to the southwest between Lee and his lines of communication. Lee's weakness is his RIGHT, not his LEFT. Jackson can fall back

 

[JerryD]

Pope has always been a bit of an enigma to me. He seems to have been a competent commander everywhere he went EXCEPT the eastern theatre, and he seems to have antagonized not only the CSA but also his own army. I have never understood how it was possible that he simply ignored the presence of the First Corps on his flank, or how he thought Jackson was retreating when his generals kept telling him Jackson was still manning his line. He does seem to have been somewhat delusional at this time.

 

[Stone in the wall]

Had Pope sent more troops to defend Thoroughfare Gap it would have made a strong defensive position to block Longstreet and given Pope time to deal with Jackson. Then deal with Longstreet. Although I don't know if Pope was capable of making good decisions.

 

[Kerry Won Ohio]

Pope makes two major mistakes at Second Manassas.

1. Union attacks over a day and a half are uncoordinated. He squandered his numerical superiority over Jackson. The Confederate line was good but by no means unbreakable as the Union attacks came close at least once to piercing the line - close enough for some of Stonewall's men to literally throw rocks at the Yankees.

2. Pope has one of the worst cases of tunnel vision in military history. He is completely focused on attacking Jackson and dismissive of Longstreet's potential arrival.

Let us do a little armchair generaling. This isn't really a What If, but more a What Should Have Been.

If Pope successfully coordinates a large attack on the afternoon of Aug 29, what is the best part of Jackson's line to make and exploit a breakthrough?

Can Pope launch a dawn attack on Aug 30 anywhere with any chance of success, or does Longstreet's attack ensure even an optimal attack is rendered irrelevant by the end of the day?

If Pope recognizes Longstreet's arrival on Aug 29 - perhaps McDowell visits Porter, recognizes the threat, and persuades Pope it is a serious threat - what is the best course of action for the Union Army? Do they need to withdrawal across Bull Run during the night? Should Porter remain where he is off Longstreet's right flank and the rest of the Army shift southward to form a line connected to Porter?

The Union definitely could have won at Second Manassas. Stonewall Jackson was close to buckling under the repeated Union attacks.

Longstreet arrived and saved the day for the Confederates.

 

[38th Georgia]

Agree with the stronger defense of Thoroughfare Gap as a contributor to a possible Union victory.

Hitting the brigades (Stonewall, Trimble and Lawton) that had not only gone thru the hard marching up to the Manassas area, and fought King's division to a bloody stand still at Brawner's Farm been hit hard with solid support to follow up any break thru could be seen as a potential key to success.

On a completely different thought, what Pope had "gone Jackson" on Jackson and hit A.P. Hill from Sudley Ford? Some of Hill's troops were hanging on by their fingernails with the frontal attacks. They were exhausted and low on ammo. Getting flanked could have been a breaking point and result in rolling up Jackson's left.

 

[13 IL Cav & 64 GA Inf]

What if Jackson saw that he would be outnumbered and decided to withdraw a few miles to wait for support? Then, I have no idea how the eventual battle would have developed, but it would probably have been more favorable for the Union.

 

[LibertyAndUnion]

The best way for that battle to be won is never to have fought it. Halleck should've ordered Pope back to DC defenses/Centreville to reunite with the the entirety of the Army of the Potomac. The campaign of disunited forces managed by the utterly incompetent Pope had no chance.

 

[Andy Cardinal]

The best way for that battle to be won is never to have fought it. Halleck should've ordered Pope back to DC defenses/Centreville to reunite with the the entirety of the Army of the Potomac. The campaign of disunited forces managed by the utterly incompetent Pope had no chance.

Agree with this take. There was absolutely no reason to fight -- except Pope had little idea of what was actually going on and thought he could "bag" Jackson. I believe Pope was desperate to fight and win without the entirety of the Army of the Potomac.

 

[Josh The Lighthouse Guy]

The best way for that battle to be won is never to have fought it. Halleck should've ordered Pope back to DC defenses/Centreville to reunite with the the entirety of the Army of the Potomac. The campaign of disunited forces managed by the utterly incompetent Pope had no chance.

Destroying one wing of Lee's army before the other wing arrives is good
idea - defeat in detail. The execution was the problem.

 

[jackt62]

Lincoln's order creating Pope's Army of Virginia reads in part as follows:

"The Army of Virginia shall operate in such manner as, while protecting western Virginia and the national capital from danger or insult, it shall in the speediest manner attack and overcome the rebel forces under Jackson and Ewell, threaten the enemy in the direction of Charlottesville, and render the most effective aid to relieve General McClellan and capture Richmond."

Problem with the mission given the AoV was its wide-ranging tasks and non-complementary tasks. While it made a certain sense to consolidate the defeated Union forces in the Shenandoah Valley, that door had already closed as Jackson and Ewell were no longer the main threat in that area. At the same time, the AoV was to help McClellan in his already desperate attempt to capture Richmond, yet simultaneously maintain sufficient force to protect Washington. The contradictory nature of these assignments led to task overload, which a highly competent commander might have been able to juggle. But Pope was primarily brought in from western command in order to instill the eastern army with more aggressive tactics, in contrast to McClellan's perceived kid gloves approach to fighting the war.

 

[Josh The Lighthouse Guy]

At the same time, the AoV was to help McClellan in his already desperate attempt to capture Richmond, yet simultaneously maintain sufficient force to protect Washington.

By moving at Richmond overland from the north Pope was protecting Washington, unless outflanked.

 

[jackt62]

By moving at Richmond overland from the north Pope was protecting Washington, unless outflanked.

True, if that were his only mission.

 

[Kerry Won Ohio]

Agree with this take. There was absolutely no reason to fight -- except Pope had little idea of what was actually going on and thought he could "bag" Jackson. I believe Pope was desperate to fight and win without the entirety of the Army of the Potomac.

I don't think it was necessarily desperation. Pope thought he could destroy Jackson's corps before the rest of Lee's army arrived.

 

[Andy Cardinal]

I don't think it was necessarily desperation. Pope thought he could destroy Jackson's corps before the rest of Lee's army arrived.

Yes he thought so. But not understanding or refusing to understand the whole situation doomed him.

 

[LibertyAndUnion]

I don't think it was necessarily desperation. Pope thought he could destroy Jackson's corps before the rest of Lee's army arrived.

It's not a virtue for a general to act on what he thought if he was as ignorant of strategic and tactical reality as John Pope.

 

[Saphroneth]

So my basic analysis is like this, for what it's worth:


- Pope certainly had a greater total strength in the area of operations. Even completely ignoring Banks' corps, and assuming that no further troops arrive from Alexandria, Pope still had a significant advantage in total strength - about 80,000 men PFD in infantry corps, while Jackson and Longstreet combined were probably no more than about 55,000 men PFD in infantry corps. Pope has, by various means I've tried to use to work it out, a 3:2 advantage plus cavalry superiority.

- The actual battle of Second Bull Run (as begun on the 28th with the main fighting on the 29th and then 30th) could have been a victory with better coordinated attacks; that is, if Pope had on the 29th realized that he was dealing with a frontal attack on an entrenched enemy position and acted accordingly, or tried flanking around both flanks at once (with his stronger force), then he could have come out with a victory.

- In addition, Pope could have had more reinforcements if he'd tried. The thing preventing 6th Corps being sent forward earlier was lack of scouting and lack of information on what was going on; Pope could have sent some of his ample cavalry towards Washington to verify that the road was clear for 6th Corps, and brought them in.

- However, the greater advantage is a day or two earlier.

I used the consolidated numbers from later.
Refresher on strengths:
11th Corps, Kearny's division, Hooker's division, 9th Corps and 5th Corps are all about the same strength as manoeuvre units, very roughly 40% of Jackson's corps each or a bit less (though they do vary).
1st Corps (McDowell's) is about 2-3 times that size.


I have not shown 2nd Corps AoV here (Banks' corps) because Banks is guarding the army's trains. As of this point, Pope knows where Jackson is but he does not know where Longstreet is; he could, however, determine that there was a risk of Longstreet following Jackson's route in, and - importantly - he also independently benefits from blocking Thoroughfare Gap to avoid that being Jackson's route out.

Historically Pope basically had all his units converge on Manassas Junction to try and crush Jackson, but was then stymied when Jackson had moved out of the way first.

I think that it is realistic, with what Pope knew - presuming that Pope was, well, better at operational art - for him to do the following:


- McDowell's entire corps (effectively the left wing of the army) is assigned to block the passes through the Bull Run Mountains. Ricketts to Thoroughfare Gap, King in support (and able to block the roads over the passes), while Reynolds goes north to Aldie's gap.
- Hooker is ordered to Manassas Junction, and if the enemy is not found there to go to Centreville; only then is Hooker to converge on Jackson's position, even if Jackson has gone NW instead of NE.
- Kearny and Porter are both ordered to Manassas Junction, and if the enemy is not found there to follow him (presumably north). If the enemy has gone to Centreville then Porter is to turn N instead of following Kearny.
- 11th Corps is to follow the Warrenton turnpike towards Centreville, and to halt around Groveton (with the intent of blocking Jackson if he heads north).
- 9th Corps to head north to the Warrenton turnpike and support 11th Corps.


Meanwhile cavalry goes to bring in 6th Corps, probably via Fairfax and Centreville. They'll take a couple of days to arrive but that's fine; the goal is to actually have them en route, where Pope historically did not.


The intent here is to spread a net to catch Jackson and then divert all forces to converge on Jackson once he makes contact with one of them. Jackson can only get out of this trap by withdrawing south, crossing the Cedar Run, but if he does that's still a net Union strategic benefit because now the armies can be united as per the original objective.

If Longstreet is coming up from the southwest then Pope's whole army is by definition moving northeast and so Longstreet has a stern chase to deal with, and once it's confirmed where Longstreet is Pope can re-evaluate his dispositions; if Longstreet is coming from the same direction Jackson moved, then McDowell's corps will block him from getting involved.


Given Jackson's actual route of march, the likely outcome is:

Jackson collides with 11th and then 9th Corps around Groveton, and once that fighting starts a few miles away Hooker turns west and Kearny and Porter move north, coming at Jackson from several directions. Ricketts and King are occupied heavily by Longstreet (who probably cannot punch through Thoroughfare Gap, those two divisions of McDowell are about 2/3 the strength of Longstreet's entire corps and occupy a very narrow and good defensive position), but once both Confederate corps are localizzed Reynolds can be diverted from Aldie's Gap to come and help out with Jackson if necessary.


The result of all this is that about twice Jackson's strength (or more, counting Reynolds) is concentrated on him from multiple sides. That doesn't guarantee Union victory but it makes it really quite likely.