Streetwise Professor

September 21, 2023

The Rock of Chickamauga, Reconsidered

Filed under: Civil War,History,Military — cpirrong @ 3:07 pm

One hundred sixty years ago, the battered Union Army of the Cumberland gathered at Rossville, Georgia, near Chattanooga, Tennessee, in the aftermath of its catastrophic defeat at the Battle of Chickamauga, 18-20 September, 1863. Fortunately, logistical difficulties and the inevitable disorganization following a battle in which the victors had suffered 30 percent casualties prevented the Confederate Army of Tennessee from pressing their advantage. Consequently, the Army of the Cumberland was able to shake itself into a semblance of order at Rossville, and retreat into the defenses of Chattanooga on the 22nd.

Chickamauga was the second bloodiest battle in the Civil War, with casualties in excess of 34,000 out of roughly 125,000 men engaged. It was by far the most decisive Confederate victory west of the Appalachians, yet it was barren of strategic results. The Army of the Cumberland survived to fight another day. Besieged in its works, it neared starvation but the Lincoln administration rushed reinforcements from the Army of the Tennessee in the Mississippi River valley (under Grant and Sherman) and from the Eastern Theater (under Joseph Hooker). These forces opened a supply line, and eventually in late-November launched assaults that drove the Confederates in precipitate flight into northern Georgia.

(My grandfather’s great aunt Amanda Roberts remembered seeing trainloads of Union soldiers trundling through southeastern Ohio on their way to Chattanooga. It was an eventful summer for her. Earlier, she and her family had fled to the woods with their animals to escape John Hunt Morgan’s raiders.)

Rather than fighting the Yankees, after Chickamauga the Confederate generals fought one another. Or more accurately, Longstreet, Buckner, D. H. Hill and others fought army commander Braxton Bragg. Chickamauga was a bitter victory.

The battle was a meeting engagement fought in deep forests, which resulted in confused and confusing actions. On the first full day of action, neither side knew quite where the other was, and plunging into the woods time and again they came unexpectedly upon their adversaries, to their mutual surprise. For much of the second day, the battle took place along a relatively static line to which the Union army had withdrawn on the night of the 19th.

The actions included the attack of Cleburne’s division:

These troops are firing at my great-great grandfather, George Immel of the 92nd Ohio Volunteer Infantry, located a few hundred yards in their front. They missed! (Luckily for me. Perhaps due to the rude log breastworks that the Union troops had erected in the night. They also missed at Missionary Ridge, the entire Atlanta Campaign, the March to the Sea, and the Carolinas campaign. George returned home to sire eight children.)

Few commanders came out of the battle with burnished reputations: many saw their reputations destroyed. Union army commander William S. Rosecrans was relieved by Grant when the latter arrived in Chattanooga a few weeks after the battle. As noted before, Bragg’s management of the battle and the barren results resulted in widespread criticism throughout the South.

Only James Longstreet and George Thomas emerged from the battle looking good–and Longstreet soon undermined that by his squabbling with Bragg, his failure to prevent the Union from opening a supply line through Lookout Valley, and the disaster of his Knoxville Campaign. Thomas went down in history as the Rock of Chickamauga for his stalwart defense of Horseshoe Ridge/Snodgrass Hill on the 20th. His defense saved the Union army from utter destruction.

It must be said that the Union defense was only made possible by the decisions of small bodies of men to rally on Horseshoe Ridge, and later Reserve Corps commander General Gordon Granger’s decision to march to the sound of the guns without orders.

Thomas’ defense overshadows some dubious decisions.

Although by reputation a cautious and deliberate general (his knickname was “Old Slow Trot”), on the 19th Thomas ordered two divisions to attack into the woods on the basis of sketchy information. One of these decisions (Baird’s) was routed, and the other (Brannan’s) was roughly handled. Rosecrans’ army was in a false position, in danger of being cut off from its base at Chattanooga: Thomas should have established a solid line to protect the army’s line of communication (the Lafayette Road) and performed reconnaissance to find out where the Confederates were rather than plunging into the unknown.

On the night of the 19th-20th, and through the morning of the 20th, Thomas constantly importuned Rosecrans to reinforce the left (which Thomas held). (He sent something like 20 couriers to Rosecrans asking for the latter to send Negley’s division to the left.)

Now, it was the case that the left had to be held to prevent Bragg from interposing his army between Rosecrans and Chattanooga. That said, Thomas had easily repelled the attacks on his direct front (due in large part to those rudimentary log works), and those Confederates (of Breckinridge’s division) who did circle around Thomas’ left were defeated in detail. Moreover, Thomas had a reserve line in Kelly Field that could have been used to extend his flank beyond the Lafayette Road.

Moreover, Thomas was myopically focused on is own situation, and ignored the truly parlous situation of the Union right, which had been hammered the day before. The far right was held by Davis’ small division, that had been handled roughly in Viniard Field. Next to Davis was Wood’s division: Buell’s brigade of that division had also been hammered there.

Thomas’ constant call for reinforcements led the mercurial Rosecrans–whose judgment was probably clouded by an extreme lack of sleep–to make hurried adjustments to his line, pulling out some units to send them to Thomas and shuffling in other troops to fill the gaps thus opened up. This led to considerable confusion, not least in Rosecrans’ understanding of his dispositions. When he received a report of a gap between Woods’ and Reynolds’ divisions (the 92nd Ohio being in Reynolds’ outfit)–a gap that did not exist, but was in fact held by Brannan’s division–Rosecrans order Wood to pull out and “support” Reynolds. This opened a gap into which tragically or fortuitously, depending on your rooting interest, Longstreet’s powerful attack of four divisions poured. The entire Union right was routed, and the detritus of the smashed units–and one relatively intact one, Harker’s brigade of Wood’s division–formed the forces on Horseshoe Ridge.

Rosecrans probably deferred to Thomas due to fatigue, and the evident psychological dominance of the latter over the former. Regardless of the cause of Rosecrans’ deference, the confusion and shifting of troops caused by Thomas’ insistence on being reinforced set the stage for disaster.

Rosecrans is of course ultimately to blame because it was his responsibility to consider the position of the entire army. But Thomas pushed a psychologically fragile commander into bad decisions.

One pet peeve. I noted earlier that Thomas’ final defense occurred on what is known as “Snodgrass Hill,” a bald spur of the wooded Horseshoe Ridge. The monuments for Harker’s brigade are all located there, and it is undisputed that the repeated volleys of Harker’s brigade (the soldiers expending 100 rounds per man) were essential to Thomas’ defense.

But whom were they shooting at? The only Confederate unit in the area, Humphrey’s brigade from the Army of Northern Virginia that Longstreet brought to Georgia, suffered few casualties, and did not report making any attacks, let alone the numerous attacks directed at Harker. It was hundreds of yards south of Snodgrass Hill, and the accounts of the attacks on Harker’s line all indicate that the Confederates made it within a few yards of it.

Years after the battle, Archibald Gracie, the son of the commander of the Confederate brigade that finally breached the Horseshoe Ridge line (also named Archibald) wrote The Truth About Chickamauga, a sometimes polemical revisionist account which disputes the placement of the monuments, and the official War Department (later Park Service) account. Gracie’s book was based on a meticulous study of the Official Records and extensive correspondence with veterans of the combat there. I have always found Gracie’s case to be persuasive, but every modern account repeats the official version. The otherwise excellent Maps of Chickamauga, for example, has Harker’s brigade firing those tens of thousands of rounds at Humphrey’s distant (and stationary) troops.

Gracie more plausibly placed Harker’s brigade on what is referred to as “Hill One” of Horseshoe Ridge. That makes much more sense for many reasons.

Gracie is an interesting character. He survived the sinking of the Titanic, and wrote a book about it, though he died from the effects of the ordeal before it was published. Gracie Mansion in New York is named for one of his forebears (also Archibald). His father was killed at Petersburg.

Postscript: I edited this post to change the references to “Opdyke’s brigade” to “Harker’s brigade.” Opdyke commanded the 125th Ohio in Harker’s brigade.

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  1. 1. The Union left was essentially in the air by daybreak on September 20 and that was precisely where the initial Confederate attacks hit. And while by this time the Union units were mixed up rather well, Thomas’ defense around Kelly’s field involved brigades from all three Union corps, Negley’s division was a XIV Corps division and was on the opposite side of the battlefield from Thomas. It was a natural request for a corps commander to request that his third division be forwarded to him for his tactical control. While it may have been impossible, given the limited south to north communication axis of the Army of the Cumberland on the night on Sept 19 and the total confusion after a day of hard fighting in the woods (I live just north of Chatanooga and walk these fields often, it would have been a hard battlefield to move around), Negley’s division should have been deployed much earlier on the left than what actually occurred. If they are deployed sooner, then Thomas would have had all of the manpower needed.

    2. I am not sure what you are really talking about regarding the defense of Horseshoe Ridge. Horseshoe Ridge was actually a series of three hills. Opdyke’s regiment was not the only “intact” unit on the field, and it was not the only one that held the heights. The right on Hill 3 was held by Steedman’s division, the two brigades of Gordon Granger’s Reserve Corps. The center was held by mixed XIV Corps units from Negley’s and Brannan’s division, including the 21st Ohio who had repeating rifles and probably fired more rounds than any other Union regiment. Hill 1 was defended by Harker’s Brigade, which Opdyke’s 125th Ohio regiment was a part of. The Confederate attacks on the various sections of Horseshoe Ridge were a bit disjointed and uncoordinated. THis allowed Thomas to rotate his troops at the front a bit and replenish their ammunition supply.

    Comment by MARK — September 22, 2023 @ 11:59 pm

  2. hey craig, this is an excellent narrative – I dig your histories.

    Comment by john sodergreen — October 10, 2023 @ 7:11 am

  3. @john sodergreen–Thanks, John. I hope all’s well.

    Comment by cpirrong — October 10, 2023 @ 4:32 pm

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