Wednesday, June 24, 2009
Four Days in July: Setting the Stage: Second Bull Run
[Note: Made a few edits at 10:30 central time. Explanation at bottom.] Lee might have won the Seven Days’ Battles, but he was in trouble. McClellan was still sitting outside Richmond with a viable field army. Even though Stonewall Jackson had managed to tie up a significant Union force in the Shenandoah, he’d come nowhere close to possessing the ability to destroy it. The disparate forces – Banks’, Fremont’s, and McDowell’s armies – were gathered together and put under the command of John Pope. This force was poised to move straight from Washington to Richmond, completely avoiding Lee’s Army of Northern Virginia in the process. Lee had four things on his side. The first was a concept well used by Frederick the Great, one of the greatest generals in all of history. Lee, like the generals before and since, stood on the shoulders of giants. Perhaps, though, I should back up for just a moment. Firearms entered use in European armies in the late medieval period. By the Renaissance they were well established but not necessarily well used. Early hand guns, as they were called to differentiate them from field guns, were slow, inaccurate, and nearly as dangerous to their owners as their targets. Most handgunners were not equipped to face off against heavy infantry or charging cavalry and were handicapped compared to archers by the significantly reduced effective range of their weapons. Unescorted handgunners, then, usually found themselves at a huge disadvantage on the battlefield. Melee infantry, then, continued to play a role on the battlefield. Armor was virtually useless against guns, so heavy infantry was replaced by light forces armed with long pikes who would form the first line of defense against cavalry. Cavalry changed, too. Knights disappeared, replaced by light, fast cavalry armed with sabers and, eventually, single shot pistols. The first true revolution in the gunpowder age came in the early 1600s with Gustavus Adolphus of Sweden and the New Model Army. Matchlock muskets had replaced the primitive weapons of the Renaissance, allowing more consistent fire. Gustavus Adolphus was the first to see the advantages the new weapons provided and capitalize on them. The main innovation he brought to the New Model Army was drill. Rather than unguided masses of gunners between a dozen and thirty ranks deep, Gustavus Adolphus reduced his ranks to three, allowing his forces to engage in a rolling advance. The third rank reloaded, the second rank prepared to fire, and the first rank fired. When the first rank fired the other two ranks could move up or the first could move back, allowing a continuous storm of fire and an orderly advance or retreat. Gustavus Adolphus also re-invented combined-arms tactics. He mixed cavalry in with the infantry to allow quick exploitation of gaps in the enemy line. More importantly, he pioneered the use of light, mobile field guns to provide supporting fire at key points on the battlefield. He also intentionally held forces back in order to reinforce the line in the event of imminent breakthrough or breakdown. About a century later Frederick the Great would take the next step forward in preparation for the Seven Years’ War. He refined the drill and got infantry marching in cadence. This allowed his troops to rapidly change formation, moving from route to battle formation and change their facing far more quickly than previous armies. He also made expert use of interior lines. During the Seven Years’ War Prussia was outnumbered and surrounded from the outset. The only reason Frederick the Great managed to hang on was because he was in a geographically small area surrounded by enemies who were spread out and not always moving in a coordinated fashion. The Prussian Army was able to move from one hotspot to another, then outmaneuver their enemies on the battlefield. Of course, Frederick the Great was also the beneficiary of that most fickle battlefield ally: luck. At the moment it seemed that Prussia had finally run out of steam, Empress Elizabeth of Russia died and opposition to Prussia fell apart. Sometimes that’s what it takes, though. Before I get back to Lee, it’s probably important to mention Napoleon, since he’ll be figuring in pretty soon, too. For one thing, the entire makeup of the armies on both sides owed everything to Napoleon. The basic building block of the Napoleonic army was the regiment (which was made of companies and battalions, but it was regiments that mattered on a strategic level. Eight companies of 100 made a battalion, two battalions made a regiment. In theory. In the Civil War especially those numbers were flexible). Two regiments made a brigade, two brigades made a division, three divisions made a corps (pronounced "core," with the singular and plural spelled the same). The Napoleonic corps was approximately the same length when in marching formation as a days’ march. This made the corps the ideal formation for the Napoleonic age. Civil War armies retained this structure, except there was variation in terms of how the blocks added together (for instance, Hooker’s 70,000 man force at Chancellorsville consisted of 5 corps). The two main Napoleonic strategic innovations were also at play. These were the central position and the envelopment. Central position involved the concentration of power against a foe with superior numbers. If an inferior force can hold local superiority at key points, it can win the day. Envelopment is both a strategic and tactical move. It involved moving around the enemy’s flanks while cutting off communications and threatening stores. Either way, back in the Civil War Lee had the advantage of interior lines when dealing with Pope and McClellan. As I said, though, he had four advantages. His other three advantages were named John Pope, George B. McClellan, and Henry Halleck. Hopefully everyone remembers Henry Halleck as U.S. Grant’s boss out west who wanted Grant booted from the army. His star was on the rise in the summer of 1862 specifically because of the successes of his least-favorite subordinate. Lincoln believed Halleck had the answers the Union needed, so he brought him to Washington and put him in command of the Union armies. It turned out that with generals as slow as he was Halleck was no great general. McClellan stayed put on the bank of the James River asking for reinforcements. Pope moved slowly towards Richmond, stopping to establish a supply depot at Manassas Junction. He was close to the site of the previous spring’s battle at Bull Run. As was often the case in the Civil War, the South called the battles by different names. To the Confederates that battle was known as Manassas, not Bull Run. John Pope’s Army of Virginia had just over 50,000 men. Lee had 55,000, making this particular engagement one of the few where Lee actually enjoyed an advantage in numbers. Lee’s strategic position didn’t actually allow him to take immediate advantage, though. Pope’s forces were strung out across northern Virginia and Washington was taking McClellan’s army apart a corps at a time and moving them up from the Peninsula to reinforce Pope. Lee proceeded to break one of the most important rules in the book. He split his forces in half and sent Jackson around behind Pope to hit his supplies at Manassas Junction. Lee stayed with Longstreet, who maintained position in front of Pope and gave the impression the Confederates were going to stay on the defensive. On his way to Manassas Junction, Jackson attempted his own version of Napoleon’s central position. He fought his old opponent, Nathaniel Banks, at Cedar Mountain. This time it was Jackson who held the numerical advantage and he severely mangled Banks’ force. The battle and a heat wave did manage to pin Jackson in place long enough for Pope to concentrate his forces, however. He’d missed his chance to pull a Napoleon. Confederate cavalry under JEB Stuart kept Pope distracted and the Army of Virginia couldn’t carry the attack to the heavily outnumbered Jackson. Eventually Jackson slipped through the Thoroughfare Gap and hit Manassas Junction itself. The Confederates destroyed what they couldn’t carry, then withdrew before Pope could react. Jackson then fought a short battle at Brawner’s Farm and settled down at the edges of the old Bull Run battlefield to wait for Longstreet. Pope attacked Jackson with a roughly three-to-one advantage and managed to completely bungle the entire thing. He couldn’t send clear orders to Irvin McDowell and Fitz-John Porter about an attack on the Confederate right flank, which proceeded to not really happen. Pope didn’t bother to follow up and ordered some additional feints that were beat back easily. He then decided that he was on the verge of victory. Even the imminent arrival of Longstreet’s Corps through the Thoroughfare Gap didn’t faze Pope. He decided Longstreet was there to cover Jackson’s retreat from the battlefield. No one was more surprised than John Pope when Longstreet’s Corps steamrolled the Union left flank on the morning of August 30. Meanwhile, George McClellan was about ten or twelve miles away in Alexandria with about 25,000 troops from the Army of the Potomac. It’s widely believed that McClellan intentionally stayed out of the fight in an attempt to discredit Pope. I wouldn’t argue the point… What was left of Pope’s Army of Virginia was folded in to the Army of the Potomac, which was left under the command of McClellan. Pope was sent to Minnesota to fight the Sioux. Lee once again had defeated a numerically superior force through superior strategy and tactics. More importantly, he proved yet again that the most important factor in war is to know your enemies weaknesses as well as his strengths.* His attempt to capitalize on the victory at Bull Run would lead to the single most important engagement of the Civil War. But that’s a story for another day… ------------------------------- *One thing Gustavus Adolphus, Frederick the Great, Napoleon, and Robert E. Lee during the Northern Virginia campaign had in common was that they were fighting coalition forces. It wasn't as much of an issue in the case of Gustavus Adolphus, especially since he had his own problems with allies, but Frederick's interior lines and Napoleon's central position were most effective when used to exploit gaps between allied forces. In general two armies from different nations will look to their own before looking to their allies if they're in trouble. Breaking a line at a national division in the force or preventing two allied armies from joining will generally result in the opposition pulling further apart. In the worst-case scenario one army will actually allow its ally to get defeated in detail out of its own need for self-preservation. McClellan and Pope might have been fighting for the same cause, but McClellan's ambitions and Pope's pride meant that they were effectively uneasy allies who had no intention of formulating a cohesive plan. Had Grant been in charge of the Army of the Potomac and Sherman been in command of the Army of Virginia things would have gone very differently in the summer of 1862. Of course this is the difficulty of alternate history. Sherman or Grant would probably have been able to overwhelm Jackson's Corps on day one of Second Bull Run. But against a pair of armies lead by energetic and aggressive commanders Lee probably wouldn't have taken the risks he did that brought the battle about. There's a reason Lee spent the final year and a half of the war on the defensive and unable to seize the initiative. EDIT: Made a few changes, added a pronunciation guide for the word "corps." Remembered that one of the lessons from Second Bull Run was to know your enemy. I'd intended to put that in, but apparently forgot. Also added the footnote.