Corp structure

[atlantis]

1 Was the Two-division Corp structure the optimal force structure for a Corp.
2 With a division strength of 10,000.

What do you all think is the optimal number of Divisions and division strength.

 

[Wizard of Cozz]

DH Hill was difficult but IMHO Lee made a mistake in not making him a Corp commander. ANV structured into 3 two division front line Corps led by Jackson, Longstreet, DH Hill and a reserve Corp led by A P Hill plus a 2 division calvary Corp led Stuart would have provided Lee operational flexibility with capable commanders and given AP Hill time to adjust to handling Corp duties [stress seem to agitate whatever chronic illness he was dealing with].

Read Powell on Hill. Not sure Hill was cut out for Corps command. Lee had a contentious relationship with him while he was in NC, where Hill consistently saw more men to his front than were there, thereby depriving Lee of two of his best brigades. Then at Chickamauga, he constantly worried that the Federal force was about to pounce on him. He was terrible at McLemore Cove.

Powell summing up Hill says:
"Daniel Harvey Hill was sure he would be scapegoated for the things that went wrong at Chickamauga. In fact, Hill deserves a significant share of blame in his own right. Hill's contrarian nature and gloomy, dyspeptic attitude cast a pall over Bragg's headquarters, just as had happened earlier with Lee's Virginia army. Hill's military judgments were often unsound. His advocacy of crossing the Tennessee River in early September to attack the Union XXI Corps was foolhardy and might have spelled disaster if Bragg had acted upon it. Hill's mulishness on Pigeon Mountain hampered Bragg's efforts to coordinate any attack against Negley in McLemore's Cove, and Hill's bad intelligence concerning the movements of the Union XX Corps on September 13 forced Bragg to turn away from his northern flank—at a critical moment—to deal with what proved to be a non-existent threat to La Fayette.

By the time Bragg received Hill's alarmist (and false) warnings of Federals crossing West Chickamauga Creek at Glass Mill on September 18, the commanding general was starting to routinely discount Hill's dispatches. Hill's attitude regarding the botched attack on September 20, however, did the most harm. His failure to find General Polk and receive his orders on the night of the 19th entirely disrupted Bragg's plans for the 20th. His deployment once the fighting finally commenced was poor. Hill's foolish quarrelling with Polk and Walker while Breckinridge's men desperately needed reinforcements was inexcusable. Hill compounded the errors of the morning by completely misreading the movement of the Union Reserve Corps that afternoon. He was chiefly responsible for the fact that Polk's wing played no role in the fighting for four critical hours while George Thomas's efforts were entirely focused on Horseshoe Ridge. The right wing did not rejoin the fight until well after 4:00 p.m., largely due to Hill's unwillingness to attack. Hill's performance throughout all of September 20 was unrelievedly disappointing."

 

[repman66]

The number of men most appropriate for a Corps structure depends on two things - the corps commander and the needs of the campaign.

Davout routinely commanded a corps in excess of 40,000 men and was well suited for it. Others had smaller commands most appropriate to their level of command and the needs of the service.

Having Hancock command 35,000 men is fine (especially a healthy Hancock). However, giving George Sykes or Henry Slocum 35,000 is a waste.

 

[RedRover]

So in combat, in one on one confrontations, a Union corps is at a disadvantage in numbers, in relation to a Confederate Corps?

In basic numbers the Union corps were frequently lesser than some Confederate corps. For example, before Gettysburg, each of Lee's corps pretty big. As of May, 1863, for example, Lee's first corps, under Gen. Longstreet with over 29,000 officers and men present for duty...

A.P. Hill's corps similar...

Lee's army was then reorganized into three corps of roughly 20,000 present for duty each shortly after the above, and before Gettysburg...

The Army Corps of Meade's Army of the Potomac, in comparison, were seven in number, besides the Cavalry Corps. The Army corps numbering between 8,000 and 15,000 present for duty...

 

[Wizard of Cozz]

The two corps structure didn't serve Bragg very well at Chickamauga. Corps commanders were constantly searching for help from other corps commanders, because they never had enough men for a operational reserve to push home an attack. For instance, when Breckinridge broke through on the 20th, and was able to flank Thomas' position, he called for reinforcements, but Hill had none because both divisions went in together. Then he called upon Walker to help him, but then their is command confusion over Walker vs. Hill as they're each corps commanders. Hill also made mistakes that are irrelavent to this issue as well, but the two-division structure IMO, was not well suited to the attack. On top of that many of Bragg's divisions only had 3 brigades. So you're looking at most of his corps with only 6 brigades in them, just no operational depth there.

 

[OpnCoronet]

At certain times, yes - in the East, that is. This mostly applies from the time the Confederates formally organize corps in the East (October 1862, from memory - before then Confederate corps are informal, though still larger than the binary Union ones) to the point where the Union discontinues 1st and 3rd Corps in the East and fills the other three up (March 1864, at which point Union corps are now much bigger on average).

Thanks, I find this particular thread very informative.

 

[13 IL Cav & 64 GA Inf]

It's notable how the Army of Tennessee stuck very consistently to the two-division model in 1863, unlike the AoNV, which was comfortable with several divisions per corps. Makes me wonder why: was it in imitation of the Prussians, perhaps under the influence of Hardee, who studied European tactics and organization?

Bragg briefly plussed up Hill's Corps to 5 divisions after receiving reinforcements in the lead-up to Chickamauga - notably, that was after Hardee's departure - but quickly restructured to three infantry corps and one reserve corps of two divisions each. That mirrored the Army of the Cumberland's corps organization (although each corps had 3-4 divisions). Was Bragg imitating the Prussians, Rosecrans, or neither?

Bragg may have gone up to a 5-division corps temporarily simply because some of the divisions were so small due to attrition (battle losses, etc.).

 

[Luke Freet]

Probably the most important element to this debate has to do with something that often gets overlooked: how many staff officers are available to form a functioning command unit? Generals need an adaquate staff to keep track of formations and give orders on the march or battlefield. One of the big issues the Confederates have is a lack of trained low level officers to fill staff roles. This is partly why Lee maintained a two-corps structure from Second Manassas to Chancellorsville, because of a lack of staff officers to properly command smaller corps.
If you have an army with two four division corps, and you split it into four two-division corps, that would require you to organize at least two new corps level staff echelons to command the newly organized corps.
One of the criticisms Dave Powell levied against Bragg in his Chickamauga books is that Bragg was creating brand new corps and divisions from dispirate commands, which on paper should mean more flexibility, but with a lack of staff officers, resulted in a lot of dysfunction. For example: when Hood was given command of a corps, he took his divisional staff up to the corps level; in his place, his senior brigadier (Law) took his brigade staff to command at the divisional level. This left Law's Brigade under Colonel Sheffield with no staff to work with. It could have been better organizationally for Bragg to just assign all the incoming troops to Polk, D. H. Hill and Longstreet, as those were the existing corps with their already established staff echelons.
Just my two cents to the convo

 

[Wizard of Cozz]

Probably the most important element to this debate has to do with something that often gets overlooked: how many staff officers are available to form a functioning command unit? Generals need an adaquate staff to keep track of formations and give orders on the march or battlefield. One of the big issues the Confederates have is a lack of trained low level officers to fill staff roles. This is partly why Lee maintained a two-corps structure from Second Manassas to Chancellorsville, because of a lack of staff officers to properly command smaller corps.
If you have an army with two four division corps, and you split it into four two-division corps, that would require you to organize at least two new corps level staff echelons to command the newly organized corps.
One of the criticisms Dave Powell levied against Bragg in his Chickamauga books is that Bragg was creating brand new corps and divisions from dispirate commands, which on paper should mean more flexibility, but with a lack of staff officers, resulted in a lot of dysfunction. For example: when Hood was given command of a corps, he took his divisional staff up to the corps level; in his place, his senior brigadier (Law) took his brigade staff to command at the divisional level. This left Law's Brigade under Colonel Sheffield with no staff to work with. It could have been better organizationally for Bragg to just assign all the incoming troops to Polk, D. H. Hill and Longstreet, as those were the existing corps with their already established staff echelons.
Just my two cents to the convo

100% where I'm at!

 

[67th Tigers]

At Chickamauga, the rebels had 5 corps and 11 infantry divisions:

1st Corps, AoT (Polk): Cheatham and Hindman
2nd Corps, AoT (DH Hill): Cleburne and Breckinridge
3rd Corps, AoT (Buckner): Stewart and Preston (but see Longstreet)
Reserve Corps, AoT (Walker): Walker and Liddell
Longstreet's Corps (Longstreet): Hood and McLaws (1st Corps, ANV), and Bushrod Johnson (detached from Buckner's Corps)

The 3rd Corps was the old independent corps in East TN. All three corps of the AoT had three divisions, but he detached a division from each corps, to make a reserve corps, and then sent one of those the Longstreet, as McLaws hadn't arrived at the start of the battle.

However, on 20th September, Bragg reorganised the corps into two wings, of 5 and 6 divisions respectively:

Right Wing (Polk)
2nd Corps (DH Hill, 6)
Reserve Corps (Walker, 5)
Cheatham's division (5)
= 16 brigades

Left Wing (Longstreet)
Hindman's division (3)
3rd Corps (Buckner, 6)
Longstreet's Corps (Hood, 8)
= 17 brigades

The reorg was dumb. The two divisions of 1st Corps were split up, and Polk and DH Hill weren't in contact and so the wing didn't act as such.

 

[Saphroneth]

Probably the most important element to this debate has to do with something that often gets overlooked: how many staff officers are available to form a functioning command unit? Generals need an adaquate staff to keep track of formations and give orders on the march or battlefield. One of the big issues the Confederates have is a lack of trained low level officers to fill staff roles. This is partly why Lee maintained a two-corps structure from Second Manassas to Chancellorsville, because of a lack of staff officers to properly command smaller corps.

On a similar note, my understanding is that the AoP divisional staffs as originally established were pretty small and the corps staffs non-existent - each of the new CCs basically just had to take their existing DC staff with them.

 

[Wizard of Cozz]

At Chickamauga, the rebels had 5 corps and 11 infantry divisions:

1st Corps, AoT (Polk): Cheatham and Hindman
2nd Corps, AoT (DH Hill): Cleburne and Breckinridge
3rd Corps, AoT (Buckner): Stewart and Preston (but see Longstreet)
Reserve Corps, AoT (Walker): Walker and Liddell
Longstreet's Corps (Longstreet): Hood and McLaws (1st Corps, ANV), and Bushrod Johnson (detached from Buckner's Corps)

The 3rd Corps was the old independent corps in East TN. All three corps of the AoT had three divisions, but he detached a division from each corps, to make a reserve corps, and then sent one of those the Longstreet, as McLaws didn't arrive at the start of the battle.

However, on 20th September, Bragg reorganised the corps into two wings, of 5 and 6 divisions respectively:

Right Wing (Polk)
2nd Corps (DH Hill, 6)
Reserve Corps (Walker, 5)
Cheatham's division (5)
= 16 brigades

Left Wing (Longstreet)
Hindman's division (3)
3rd Corps (Buckner, 6)
Longstreet's Corps (Hood, 8)
= 17 brigades

The reorg was dumb. The two divisions of 1st Corps were split up, and Polk and DH Hill weren't in contact and so the wing didn't act as such.

As Luke noted above the lack of full staffs was a major issue.

I'd argue all of the divisions were also dramatically small. Outside of Cheatham's 5 brigade division, every other division was triangular, except for Lidell's which only had 2 brigades.

Polk (8 brigades)
- Cheatham (5 bds)
- Hindman (3 bds)
Hill (6 brigades)
- Cleburne (3 bds)
- Breckinridge (3 bds)
Buckner (6 bds)
- Stewart (3 bds)
- Preston (3 bds)
Walker (5 bds)
- Gist (3 bds)
- Lidell (2 bds)
Longstreet (12 brigades, only 8 at the battle)
- Johnson (3 bds)
- Hood/Law (5 bds - only 3 at battle)
- Mclaws (4 bds - only 2 at battle)

Outside of Longstreet and Polk his other corps are barely large divisions. The smarter move would of been for Walker to take command of his division and Liddell's two brigades to go back to their parent divisions of Cleburne and Hindman. For Buckner to simply command his division and it be attached or for Buckner to simply command. Bragg just moved brigades around willy nilly.

Something like the following made more sense IMO.

Polk (9 Brigades)
- Cheatham (5 TN Bds)
- Hindman (Anderson, Deas, Manigault, Walthall)

Hill (10 brigades)
- Cleburne (Wood, Deshler, Lidell, Polk)
- Breckinridge (Helm, Adams, Stovall)
- Stewart (Bate, Brown, Clayton)

Buckner "Reserve Corps" (9 brigades)
- Preston (Gracie, Kelly, Trigg, Johnson)
- Walker (Gist, Wilson, Gregg, Ector, McNair)

Longstreet (9 brigades)
- Hood (Law, Benning, Texas, Jenkins, Anderson)
- McLaws (Kershaw, Humphreys, Wofford, Bryan)

When Longstreet arrives, Bragg could easily have transferred a division from the Reserve corps or placed the reserve corps under Longstreet, with Buckner resuming his command of his division.

The other possibility is that Walker's division is attached to Polk and Buckner's division goes to Longstreet, giving all three corps three divisions.

Polk - Cheatham/Hindman/Walker
Hill - Cleburne/Breckinridge/Stewart
Longstreet - Hood/McLaws/Buckner

 

[Saphroneth]

Based on checking that link I provided earlier, it looks like the number of Royal Engineers on the staff of a British corps is about twice the size of the typical size of a complete corps staff in the AoP or AoNV in 1862 (when they're broken out separately on returns, that is).

 

[BCD]

Bragg may have gone up to a 5-division corps temporarily simply because some of the divisions were so small due to attrition (battle losses, etc.).

In that particular case (late Aug/early Sep) the extra divisions were freshly-arrived reinforcements marching straight from the train platform to Hill's sector north of Chattanooga. It was really an emergency measure: Buckner hadn't yet fallen back behind Hiwassee, leaving the Confederate right exposed in the exact area where Rosecrans was telegraphing a left hook - Hill needed every soldier he could get.

By the time Bragg issued the evacuation order on 6 September, he had reorganized the AoT into 6 corps (3 infantry, 1 reserve, 2 cavalry) following his preferred 2-division structure.

 

[13 IL Cav & 64 GA Inf]

In that particular case (late Aug/early Sep) the extra divisions were freshly-arrived reinforcements marching straight from the train platform to Hill's sector north of Chattanooga. It was really an emergency measure: Buckner hadn't yet fallen back behind Hiwassee, leaving the Confederate right exposed in the exact area where Rosecrans was telegraphing a left hook - Hill needed every soldier he could get.

By the time Bragg issued the evacuation order on 6 September, he had reorganized the AoT into 6 corps (3 infantry, 1 reserve, 2 cavalry) following his preferred 2-division structure.

Thanks.