Saturday, December 22, 2012

Sun Tzu at the Battle of Glorieta Pass

The following post presumes some knowledge of "The Art of War." (Chinese title, "Sun Tzu Bing Fa" meaning "Master Sun's Military Method.") I also recommend the book "Sun Tzu at Gettysburg" by Bevin Alexander and the Teaching Company's lecture series "The Art of War" by Andrew Wilson.

One quickly sees how strategy in the American Civil War's little-known New Mexico Campaign reflected the personalities of the theater commanders, each of whom was deeply flawed while yet possessing one or two favorable qualities. The Union commander, Col. Edward Richard S. Canby (by the end of 1862 promoted to general), was the military governor of New Mexico Territory. He would later be described by Gen. U.S. Grant as “insufficiently aggressive” in war but an able and even indispensable administrator in peace. Canby’s thoughtful preparation for the impending Confederate invasion rather than his battlefield acumen significantly contributed to the ultimate defeat of the Confederate campaign. Intelligence—or lack of it on the Confederate side—proved crucial when Canby intercepted a letter that revealed the Confederate commander’s intentions many months ahead of time. Secrecy and surprise having been denied to the Confederates, greater speed might have made up for it, but this proved impossible for them*, allowing Canby time to use his strength as an organizer to improve his defenses.


The Confederate commander was General Henry Hopkins Sibley. (Not to be confused with his distant cousin, General Henry Hastings Sibley, who served the Union by fighting Native Americans in the Dakotas and eventually became governor of Minnesota!) Much the opposite of the deliberate Canby, Sibley was a dreamer—impetuous, creative and romantic, and he only rarely manifested these qualities in good ways. (He is remembered by some as the inventor of the Sibley tent and Sibley stove, each of which, not coincidentally, resembles a teepee.) Indeed, it was his propensity for bragging about his pipedreams that moved him to share his invasion plans in the letter that his adversary intercepted. His intelligence gathering was limited to memory of his experience in New Mexico from the late 1850s up until mid-1861, and he apparently did not know about or did not appreciate the significance of the drought conditions that developed after his departure from the territory. He also did not know that Canby would use his lead time to improve major fortifications, rendering them more impregnable than Sibley remembered. His previous career in the United States Army had been checkered to say the least, including a court martial for insubordination in Wyoming in the 1850s. A couple of years after the New Mexico Campaign, his alcoholism would lead to a Confederate court martial in Louisianafor dereliction of duty. Alcoholism and dereliction also characterized his leadership in New Mexico, but he had excellent subordinate officers who provided better tactical leadership than Sibley could have. Nevertheless, Sibley’s plan, despite his leaking it to Canby, was so bold that even though Canby warned the War Department of it, hardly anyone in Washingtonbelieved it; consequently, Canby received no support and was forced to plan the defense of New Mexicoon his own. Moreover, once Sibley got past the Battle of Valverde Ford, fought on the Rio Grande at the end of February, he rapidly captured Socorro, Albuquerque and Santa Fe before sending his men on to Fort Unionwhich was the only obstacle to the capture of the Santa Fe Trail.


The place of the New Mexico Campaign in the whole strategy of the Civil War is worth mentioning. The rationale in Richmond, where Confederate President Jefferson Davis met and was overly impressed with Sibley, was that capturing territory out West would be beneficial only if it could be done cheaply. Sibley’s overconfidence that he could do a great deal for almost no money induced Davisto give his approval to the scheme. Sibley was not completely mad, however, and his scheme had its merits. In Washington, the War Department early on determined that it needed trained men to fight in the East, so it drew soldiers out of the western territories. This left the various outposts short-staffed and induced Native American warriors to raid civilian ranchers without much fear of reprisal. Since Washington deemed the Civil War in the East to be more important, this drain made sense, but it meant that Canby and other territorial commanders had to make do with less, and the failure to protect frontier civilians enraged many of them, particularly in the New Mexico Territory where some came to support the Confederate takeover of the territory’s southern tier, which was renamed “the Confederate Territory of Arizona.” Some pro-Confederate residents of this territory provided Sibley with volunteer reinforcements.


When the War Department heard in March that Sibley had captured the territorial capital of Santa Fe, Secretary Edwin Stanton doubted his overall strategy for the first time. Should troops be sent from the East to the West, reversing the one-way policy up to that point? General Henry Halleck was asked to render an opinion. After studying the situation, he assured Washington that Canby had matters in hand, and the idea of sending troops west was dropped; but obviously if the Confederates had not been stopped before taking control of the Santa Fe Trail, then Washington would have been forced to send troops into the West, thereby altering the course of the war, not to mention history, which would now have to take note of these events rather than ignoring them as it has.


Like a good Suntzean general, Sibley intended to have his oversized brigade—which he styled “The Army of New Mexico”—live off of the land, but he did not count on two things. Firstly, the drought in New Mexico in 1862, which made foraging a time-consuming challenge for his men and animals; secondly, the fact that Canby had given his troops orders to destroy or hide all supplies before any retreat. In only one instance was this order not obeyed, resulting in Sibley capturing some supplies at Socorro, but when he took Albuquerque and Santa Fe, he was soon starving for supplies. (Louisa Canby, the colonel’s wife and Sibley’s captive at Santa Fe, took pity on the sick and wounded Confederates and showed them where medical supplies and blankets had been hidden, but evidently weapons and ammunition had either been hidden separately or more thoroughly destroyed.)


Probably one of the most brilliant things that Canby did was to use knowledge of weather to his advantage. He reasoned that, since there was a drought, the Confederates would be forced to invade via a river that could sustain a large force of men and animals. He concluded that only three rivers would be suitable and, since two of the rivers were close together, Canby only had to divide his meager forces into two parts rather than spread them along the entire border between New Mexico and Texas.


Another wise move was the reinforcement of his small professional army with volunteer units. Canby actively campaigned to raise New Mexico volunteers and delegated a significant part of the recruitment task to the territorial governor—an Anglo who spoke fluent Spanish. (Unfortunately, the New Mexico units were poorly trained except for the First New Mexico Volunteers which was led by Col. Kit Carson.) Canby also persuaded the territorial governor of Colorado to send a contingent of volunteers. While these reinforcements proved helpful, overall, there were drawbacks. The New Mexico Volunteer unit that defended Socorro was of the poorly trained variety that retreated without destroying supplies that then fell into Confederate hands. Also, the officers of the otherwise able Colorado volunteers were inexperienced. Most notably, Col. John P. Slough of the Colorado Volunteers disobeyed Canby’s order to stay inside of Fort Union and defend against any Confederate attack. Slough, a lawyer who had no military experience, went out and directly attacked the more able Confederate commander, Col. William R. Scurry. Slough lost the conventional portion of the Battle of Glorieta Pass and might well have handed the Confederate invaders their ultimate goal: Control of the Santa Fe Trail and access to Colorado and parts west, including silver mines and other resources of value to the cash starved Confederacy.


Glorieta, the last major battle of the campaign, drips with irony because of the purely accidental use of an unconventional maneuver. Though the conventional confrontation was easily won by the Confederates, an unconventional flanking maneuver—in which the novice Union commander Slough had had no particular confidence and no great interest—dealt a fatal blow to the whole Confederate campaign. Led by a major in the Colorado Volunteers and a colonel in the New Mexico Volunteers, a unit of men that was meant to outflank the Confederates instead found itself behind enemy lines and right on top of lightly guarded Confederate supply wagons, which were quickly and thoroughly destroyed with fire. Without supplies and knowing how scarce replacements would be, the Confederates soon realized that they would have to abandon their campaign, and they retreated all the way back to Texas.


Although he planned with foresight, Canby was unable to stop the advance of the Rebel brigade, and was later criticized for letting the Confederates flee back to Texasvirtually unmolested. Canby did pursue them, but, as Grant might have said, with insufficient aggressiveness. The Confederate retreat was troubled by only one light skirmish. (But Confederate moral was plagued by the fear that they might be attacked at any moment, knowing that they were vulnerable in their starving and exhausted state.)


While Canby was present at the Battle of Valverde Ford, the first major battle of the campaign (when Sibley stayed in his ambulance many yards behind the lines), Canby and Sibley were both absent from the last major engagement at Glorieta. The accidental outcome at Glorieta, as favorable as it was to the Union, was not under Canby’s control. Despite only having to divide his forces in two, Canby was nevertheless hindered by the vastness of the area he had to cover. Should he lay siege to Santa Fe, where Sibley remained while his troops marched up the Santa Fe Trail? He was undoubtedly at least somewhat worried about his wife being Sibley’s prisoner, having no way of knowing that she was being treated well. Fortunately for the Union, Sibley’s campaign—which might have presented the Union with a more formidable challenge in the hands of a more able commander—collapsed under Sibley’s mismanagement. While Canby’s organizational skills contributed significantly to the Confederate defeat, his adversary’s incompetence made the difference between the New Mexico Campaign bringing the focus of the Civil War westward or becoming a mere footnote to the war.

*While Sun Tzu would have admired Sibley's intent to live off the land in New Mexico, he would have been underwhelmed by Sibley's slowness in getting his invasion underway. About six months elapsed between Sibley's getting permission for his campaign from Confederate President Jefferson Davis and his men leaving their base camp in Texas. Logistics was the problem. Equipping his little army with leftover weapons, ammunition, animals and other supplies--in many cases, men having to provide their own uniforms and equipment--took Sibley far more time than it should have.

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