Among the commanders in the Army of the Cumberland, two men are notable for not being much noted. In fact, there is a certain amount of mystery wrapped around each of them. They are Brigadier Generals James St. Clair Morton, Rosecrans’ chief engineer, and Robert Mitchell, acting Cavalry Corps commander. They both have interesting roles to play at Chickamauga, but their stories tend to be obscured by the larger more famous dramas surrounding the battle.
James St. Clair Morton was much like a younger version of Rosecrans himself: Brilliant and meticulous, brash and opinionated. Originally from Philadelphia, he graduated from West Point in 1851, 2nd in his class, and spent the next decade on engineering projects, much as Rosey did. Morton challenged conventional wisdom on fortifications, authoring a paper on the flaws in New York’s existing harbor defenses. He was for a time chief engineer for the Washington Monument, taught at the Academy, surveyed the possibility of an isthmus canal, and built forts around the country. He saw no combat in those ante-bellum years.
He became Don Carlos Buell’s chief engineer in May, 1862, and continued on in that post under Rosecrans. As such, most of the fortifications the Army of the Ohio/Cumberland came to rely on to secure its supply lines and rear areas were conceived and built by Morton: the defenses of Nashville, the fortifications at Gallatin, Fortress Rosecrans, and numerous smaller blockhouses and RR defenses.
One of the Army of the Cumberland’s most important assets was the Pioneer corps, a hand-picked force of 20 men from each regiment – machinists, engineers, carpenters and artificers of all kinds – that provided the army with several thousand skilled laborers. Trained and administered by Morton, the Pioneers proved themselves both on and off the battlefield. They performed both bridging and combat duties at Stones River, for example. After Chickamauga, they ran the sawmills and built the pontoons that made the ‘Cracker Line’ possible. They, along with the 1st Michigan Engineers and Mechanics (who did most of the railroad work) amounted to one of the Army of the Cumberland’s ‘secret weapons’ in tackling the huge engineering challenges attendant with the difficult campaign for Chattanooga.
Morton served as Rosecrans’ Chief Engineer through the fall of 1863, and then resigned his volunteer commission to revert to the rank of regular army major. Why he did so is somewhat of a mystery. William B. Hazen, in his memoir, says it was because General Rosecrans verbally upbraided him in a most humiliating manner during the Tullahoma campaign, when, as commander of the Pioneers, he proved lax in enforcing discipline and allowed his men to slow up McCook’s XX Corps.
This story may well be true. Certainly McCook was unhappy with the Pioneers that June, and complained about it to headquarters, evidence of which can be found in the Official Records. Morton apparently tendered his resignation at the end of August. Rosecrans wired Henry Halleck on August 27th to ask who might be available to take Morton’s place. Halleck replied that Generals William F. Smith and Henry W. Benham were available. Smith got the nod, with orders cut sending him to replace Morton on September 5th, 1863. He would be a while in arriving, and miss the battle of Chickamauga. In the meantime, Morton continued to serve.
However, if McCook’s complaints and the chewing out by Rosecrans were the cause, why would Morton wait until the end of August to resign? Resigning in July, after Tullahoma, when the army paused for nearly two months and things were quiet, makes much more sense.
At the end of August the Army of the Cumberland embarked on their most ambitious campaign to date, one in which the engineering challenges posed by river and mountain would be huge.
In fact, Morton was present through the campaign, served valiantly at Chickamauga, and played an important role in organizing the defenses of Chattanooga after the disaster on September 20th. Rosecrans praised Morton in his report, suggesting that there was no lasting enmity, at least. Still, when Smith finally arrived on October 12th, Morton handed over his command and went north.
Morton was killed in June, 1864, outside Petersburg, serving as chief engineer to Ambrose Burnside, commanding the Union IX Corps. By all accounts, his was a valiant sacrifice, as he was personally guiding an assault column in order to make sure it did not go off course. He died a major of the regular army, the only Union General to resign his volunteer commission and revert to regular rank, at least according to Ezra Warner. He died young, and apparently left no papers, so the reasons for his resignation remain murky, despite Hazen’s account.
James St. Clair Morton had a profound impact on the Army of the Cumberland, for he both constructed much of the defensive and support infrastructure the army came to rely on, as well as trained and organized the men who built it. His work continued to prove it’s worth long after he left. Sherman’s advance on Atlanta rested on the bedrock of support he built, and might not have been possible without it.
Next time, a little about Robert Mitchell…