What if Union won Chickamauga?

[Hastings]

Chickamauga OTL was one of those battles only saved by being the winner. Even OTL, the Union suffered less casualties (slightly over 11k dead+wounded versus 17k, but 3k more missing/captured), despite being pretty roughly handled at the end. If the Union manages to stall Longstreet's attack, maybe by not messing up their line filling a non-existant hole, could be pretty bad. Plausible near 2-1 casualty ratio in a scenario where the Union wins, which would be the worst Confederate field defeat of the war. This moves things up several months, but it may be getting a bit late in the year to start a campaign for Atlanta. Rosecrans obviously will have a great reputation ATL, this is right after his Tullahoma campaign after all. I could see him doing quite well in the maneuver+feint style of working toward Atlanta. What happens with Grant? Vicksburg is wrapped up. Maybe he comes east early, though he was reluctant? Or maybe without reinforcements being needed for Chickamauga there is a campaign in Mississippi/Alabama or something? I assume Bragg is out, given his crushing defeat even given Davis. But who steps in? Johnston just messed up Vicksburg campaign, Longstreet is tainted by defeat as are Bragg's subordinates.

I could see the end of the war being meaningfully accelerated if Rosecrans manages to get in another campaign before winter and take or get close to Atlanta. I think Grant gets too much credit for defeating Lee versus Sherman being in North Carolina and associated problems flowing from that. But fundamentally Confederates are in for a bad time once Union gets through the mountains there, though less bad if they don’t throw away their army for the fun of it (Hood!). Though Rosecrans seems to have been a bit reluctant to advance. But in a Union victory situation the Confederates will be pretty mauled and that should be pretty clear.

 

[Arnold d.c]

If the Union manages to stall Longstreet's attack, maybe by not messing up their line filling a non-existant hole, could be pretty bad.

I think the common consensus is that even if Thomas Wood's division had been in place, Longstreet likely would have still rolled the line. With or without the gap, Jeff Davis' division still had an open right flank, which the Confederates exploited. Woods' division was also quite small and the Federals had just Sheridan and Van Cleve's mauled divisions left in reserve, the former of which was put to flight after attempting to reinforce Jeff Davis and the latter was easily routed.

Rosecrans obviously will have a great reputation ATL, this is right after his Tullahoma campaign after all. I could see him doing quite well in the maneuver+feint style of working toward Atlanta.

Without the rout at the Siege of Chattanooga IOTL, I could see Bragg being able to make a stand around Ringgold Gap before retiring to Dalton. Confederate logistics will be better relative to OTL given that they aren't as outstretched as they were at Chattanooga. On the other hand, I do see Burnside being able to reinforce Rosecrans without the rout at Chickamauga. I'm not certain if Rosecrans can make that much progress to Atlanta - the most I see is capturing Dalton - 1/4 the journey to Atlanta.

I assume Bragg is out, given his crushing defeat even given Davis. But who steps in? Johnston just messed up Vicksburg campaign, Longstreet is tainted by defeat as are Bragg's subordinates.

My answer is that it's still Johnston. Now this is coming from someone with a rather low opinion of Johnston, but it should be recalled that people liked him a lot. Polk and Longstreet would have recommended him and Hardee's whole passive-aggressive relationship with the seat of Army of Tennessee commander means he won't get it.

What happens with Grant? Vicksburg is wrapped up. Maybe he comes east early, though he was reluctant? Or maybe without reinforcements being needed for Chickamauga there is a campaign in Mississippi/Alabama or something?

That's actually a very good question. I think historian Brook Simpson points out the irony that Grant's Vicksburg victory, his best campaign, got him sidelined in a low action theater. IOTL, elements of Grant's Army of the Tennessee were being sent to Arkansas to capture the southern half of the state before being recalled for reinforcements to Chattanooga. At the same time, Grant was recommending constantly the deployment of his army to capture and seize Mobile, thereby opening another route to attack Atlanta and deny the Confederates the breadbasket of the Black Prairie. If Grant does go down this route, it's a race to Atlanta between Grant and Rosecrans. Grant has a more secure route, good foraging ground and possibly faces less troops while Rosecrans will not have to fight the troops that made Polk's Corps in the Atlanta Campaign.

 

[GTStinger]

I concur that it's very hard to achieve a Union victory just by keeping Wood in position. You would get a much more orderly fallback to the Snodgrass position, especially if Hood still falls. Hood's wounding caused a critical delay, so if that butterflies, the battle may wind up about the same. Possibly there is a draw with both sides too exhausted to fight much on the 21st, but most likely the Union still has to leave the field, albeit in better condition than OTL and less loss of prestige for Roscrans.

I can't remember the source, but I do recall a story of Longstreet and his staff taking a wrong turn near Cloud Springs as they moved from Ringgold Station to the battlefield and having to flee from a Union patrol. A captured Longstreet could make a very different battle. Bragg might abandon the entire two wing organization and instead wind up with some combination of Polk / Buckner / Hill / Hood corp structure. Maybe he also just tries to insert Buckner in Longstreet's role as wing commander.

 

[SWS]

Strategically, it would move-up the schedule by two months in Georgia and six in Virginia. The Army of the Cumberland and that of the Ohio will remain at Chattanooga and Knoxville, respectively, building-up East Tennessee's logistical service for the 1864 campaigning-season, exasperating President Lincoln and Rosecrans' antagonists in the War Department all the while, who will no doubt demand immediate movement toward the Chattahoochee. Rosecrans, a popular Democrat, would also constitute a political threat in the mind of Secretary Stanton, especially in an election year. The Grant-Rosecrans rivalry in the Western theatre will continue. The Military Division of the Mississippi will not be implemented, impeding co-ordination between the U.S. armies. Halleck's position as General-in-Chief will remain secure for the foreseeable future, and he will continue to project a fruitless offensive design against "Kirby-Smithdom" in the trans-Mississippi, impairing Grant's fixation on Mobile as veteran units of the Army of the Tennessee are "loaned" to N.P. Banks.

The C.S. Army of Tennessee will be able to rest, refit, and re-organize at Dalton, fortifying Rocky-Face Ridge in the interim. Bragg's career in the field is effectively-terminated, and I think Johnston is still the most likely successor, as Davis has more confidence in his ability than in Beauregard's at this time. The nightmarish post-Chickamauga round-robin, feuds, scapegoating, and re-assignments will not occur here, although Davis will still engage in a second "goodwill tour" of the Southern States for reasons of politics and inspection. Confederate officer morale will be raised under the "Gamecock", and eventually that of the whole Western army. Longstreet's Knoxville expedition might go forward as IOTL, depending on the status of Cleveland, Tn, although it will likely be quickly-occupied by the Federals. The national depression and discontent of OTL December 1863 would surface in October in the Confederacy, although the malaise would be relieved if Johnston is appointed to the Western command and Lee has success in repulsing Meade. The loss of the lines of the Mississippi and the Tennessee is bad, although there is still hope for grand results so long as the valleys of the Alabama, Chattahoochee, and James Rivers are not occupied by the enemy in force. The South is reduced to its very heartland. The people might yearn for a Dictator in order to repair the military and financial situation. The anti-Administration faction would be strengthened, at least rhetorically and editorially, although Congress would remain under the thumb of Davis as ever. Longstreet's Corps will return to Virginia, in any case.

Meade will likely initiate an earlier Wilderness/Mine Run campaign in October without having to detach the XI/XII Corps to the West. It could end inconclusively, or with Lee's retirement toward the North Anna and Pamunkey, where he will receive succor from the Southside and Carolina brigades.

Operations in 1864 will be quite interesting. Possession of Meridian, Miss., and Demopolis, Ala., (in an excellent foraging region) is the sine qua non for any campaign against Mobile by Grant, although Halleck will be pushing for the grand design on Shreveport, which cannot succeed in most scenarios. Rosecrans and Burnside meanwhile have options in forcing Johnston's retirement from Ridge-and-Valley Georgia, although I think Sherman's OTL army-group was essential in producing ultimate Union victory in the Atlanta campaign. Rosecrans, I think, will favor the western Chattooga Valley route toward Rome, Ga., via LaFayette, Trion, and Summerville, screening his movement with Taylor Ridge, rather than oppose the Army of Tennessee directly at Tunnel Hill or Varnell's Station (that would be Burnside's assignment with IX and XXIII Corps/cavalry). Johnston, however, would possess superior rail communications. The Army of the Cumberland would be unable to invest Rome if the city is reinforced adequately. And the Red River campaign is another speculation entirely. Imagine Grant being forced to relieve Dick Taylor's "siege" of Alexandria, lifting the spectre of an Alabama invasion, permitting Hardee to reinforce Johnston and Forrest to raid Tennessee. The Confederate Southwest would be safe for 1864, at least until after the midsummer disease season.