By the late summer of 1862, the Union Army of the Potomac was in disarray. The Confederate Army of Northern Virginia, under the leadership of rising star Gen. Robert E. Lee, was crossing the Potomac River into Maryland. Lee's army was bolstered by victories on the Penninsula and at Second Bull Run. They advanced through the fertile fields of Frederick County, Maryland to gather food and supplies, recruit what were thought to be Southern sympathizers, and to threaten Northern cities prior to the elections of 1862 in order to gain foreign support for the Confederacy.
President Lincoln had relieved Gen. George McClellan from command of all the Union forces in March 1862, during the bitterly unsuccessful Penninsula Campaign, and replaced him with Henry Halleck. While McClellan, still in charge of the Army of the Potomac, was pulling his army off the penninsula and back to Alexandria by water, John Pope's Army of Virginia was ordered to engage Lee overland from Washington. He also failed to stop the southern forces, in part, because McClellan failed to reinforce him at Second Bull Run. Frantic to stop the advancing Confederate forces, Lincoln asked McClellan to assume control over the defense of Washington, relieved Pope of his command of the Army of Virginia, and combined both forces under McClellan to engage Lee. McClellan had to organize his forces quickly. The Second Battle of Bull Run ended August 30th and Lee's advance forces crossed the Potomac on September 4th. (Clemens, 2002)
Lee's army headed to Frederick, Maryland. He was hoping to draw the Union forces away from Washington, as well as Martinsburg and Harper's Ferry in Virginia, but Halleck ordered the Union garrisons in Virginia to remain there. Lee then devised the plan to destroy or capture these garrisons. General Walker's division would take Loudon Heights, Lafayette McLaws' and Richard Anderson's divisions would capture Maryland Heights, and Major General Thomas "Stonewall" Jackson's three divisions would take Martinsburg and approach Harper's Ferry from Bolivar Heights. Major General James Longstreet headed to Hagerstown with two divisions and left D.H. Hill's division in Boonesboro to protect Fox's and Turner's Gaps. McLaws left a small force at Crampton's Gap, about seven miles south of the other passes. (Hartwig, n.d.)
McClellan divided his army up into three wings assigned to Generals Franklin, Sumner & Burnside. Franklin's wing was sent to Crampton's Gap in defense of Harper's Ferry. (Clemmons, 2002)<
As dawn broke on Sunday morning, September 14, 1862, the gunners of Chew's Battery reached the summit of South Mountain from their camp at the western base. There was a light chill in the air as temperatures would climb to the 60-65 degree range. ("Battle." 2002)
"Several miles to the east rose the Catoctin Mountains, which must have appeared at that early hour as dark, shadowy silhouettes, ... [and stretched out before them, the] ... 'beautiful Middletown Valley ... with its wooded hills, pleasant fields, hamlets, and towns reposing in the quiet calm of a peaceful Sabbath morning.' Yet that quiet calm would soon be shaken." (Hoptak, 2011, p. 131)
"Franklin's orders were to move at daybreak, on the morning of the 14th [September], by Jefferson and Burkittsville, as soon as practicable, and debouch upon Rohrersville, in Pleasant Valley, in order to cut off the retreat of or destroy McLaws's command." (Clemmons, 2002, p. 296) Starting at Buckeystown at 6:00am, Franklin's men marched the four miles to Jefferson. (Clemmons, 2002, p. 296) As the thirteen thousand men of the Sixth Corps tediously summited the Catoctin Mountain from the east, they were also stunned by the beauty of the valley stretched out before them. George Bicknell, an officer with the 5th Maine declared it was "the loveliest landscape" he had ever seen. (Hoptak, 2011, p. 132) After waiting an hour in Jefferson, they continued to their march to within two miles of Burkittsville, arriving at noon. Franklin thought that the gap was heavily guarded on both sides of the road leading out of Burkittsville with batteries at Browsville Pass and at Crampton's Gap. He knew the pass would have to be taken by infantry and assigned the job to General Slocum's divison. (Clemmons, 2002, p. 296)
Franklin, a career soldier and gifted engineer, had a reputation of not performing well in independent command, and perhaps owed his close association with McClellan to his rank of Major General, commanding the Army of the Potomac's Sixth Corps. The Sixth Corps was divided into two divisions commanded by Henry Slocum and William "Baldy" Smith. Slocum's 1st Division consisted of three brigades led by Colonels Joseph Bartlett and Alfred Torbert and Brigadier General John Newton. Smith's 2nd Division's three brigades were commanded by Generals Winfield Scott Hancock and William Brooks, and Colonel William Irwin. (Hoptak, 2011, p. 132)
"Shortly after noon, as the cannon fire began to intensify, William Franklin established his headquarters at the stately home of Martin Shafer - one mile east of Burkittsville - and then sat down to enjoy a bite to eat. He granted his footsore soldiers a reprieve, as they had covered the six miles from Jefferson in just over two hours. ... Generals Henry Slocum, Baldy Smith, Winfield Hancock, William Brooks, and John Newton soon joined Franklin at headquarters, and together the officers - essentially the entire Sixth Corps brass, excepting only Colonels Bartlett, Torbert and Irwin - enjoyed a round of cigars." (Hoptak, 2011, p. 138)
Prior to this fraternal activity, Franklin received communication from General McClellan, directing him to clear the Confederate cavalry from Burkittsville, occupy the pass, and relieve Colonel Miles in Harper's Ferry. (Hoptak, 2011, p. 138) The cannon fire mentioned in the above quote refers to Wolcott's 1st Maryland Battery (8 guns) positioned to the left of the road just out of town and Ayre's regular battery on the right of the road and far to the rear of Wolcott's, close to Franklin's headquarters. These batteries began to unload on the rebel positions prior to noon and continued uninterrupted through the battle. (Clemmons, 2002, p. 296)
Throughout the morning, Confederate General Paul Semmes tried to reinforce the Gap, but McLaws did not realize the size of the attacking Federal force, relying on erroneous information from General Stuart. Stuart had left Colonel Thomas Munford with the 2nd and 12th Virginia Cavalry, 275 men, and Chew's Battery at Crampton's Gap. Semmes had 300 men at Brownsville Pass and Munford, a total of 800 at Crampton's Gap. McLaws sent Cobb's Brigade of 1350 to the gap as reinforcements. (Hoptak, 2011)
Captain John Boyle, of the 96th Pennsylvania, gave this description of the Confederate defenses:
The enemy's infantry were posted behind a stout stone wall, breast high, which extended along a country road [Mountain Church Road] skirting the base of the mountain, which, here, was precipitous and rough...Their sharpshooters were hid and protected by the trees and boulders which cover the side of the ascent, while their artillery occupied the heights. The approach was through corn, and over stubblefields and meadows, separated from each other by stone and zig-zag fences and spotted with thickets, stone piles, rocks, gullies, and quagmires. (Hoptak, 2011, p. 140)
Back at Franklin's headquarters, the Shafer farm, the generals were mixed on which side of the defenses they should attack. When Slocum was asked who would lead the attack, he replied that Col. Joseph Bartlett would. Franklin sent for him and upon arriving at headquarters, he was asked for his opinion, which was to attack on the right, over the ground previously described.
Slocum's three brigades formed up for the attack at 3:00pm. The brigades were stacked up in six fronts each separated by 150-200 yards. George Neese, a Confederate half way up the slope described the assault this way:
...stood for awhile and gazed at the magnificent splendor of the martial array that was slowly and steadily moving toward us across the plain below like a living panorama, the sheen of the glittering side-arms and thousands of bright, shiny musket barrels looking like a silver spangled sea rippling and flashing in the light of a midday sun. (Hoptak, 2011, p. 143)
The battle began at 4:00pm. Bartlett's 5th Maine and 16th New York advanced to within 300 yards of the Confederate line, standing behind a wooden fence, firing at the enemy. For some reason not explained, Newton's brigade had not advanced. When they finally advanced to where Barlett's brigade was engaged, an hour later, they took over the fight from Bartlett's men, who were nearly out of ammunition. Torbert's Brigade quickly followed. Barlett and Torbert galloped up and down behind the lines, directing their men on, but no ground was gained. Slocum ordered Wolcott's Battery A, 1st Maryland Light Artilley, forward, through town. Lt. James Rigby later recalled that as soon as the battery turned on the road...
...the Rebels turned their guns upon us, and such as a shower of shot and shell fell around us not easily imagined; but we went through at a gallop, and as we passed through the village, the women waved their scarves and bid us God's speed, though all of them were in tears, for while they stood in front of their houses, the Rebel shells were tearing down their back fences and kitchens. (Hoptak, 2011, p. 147)
Hearing reports of activity south of town, Franklin, concerned that the Rebels might flank Bartlett's left, directed Smith to send a brigade in to the left of Burkittsville Road. Smith sent Brigadier General William T.H. Brooks' Vermonters up through the David Arnold Farm where they engaged the 2nd Virginia.
Once together, Bartlett and Torbert ordered the troops into an extended battle front nearly a mile wide, starting about 200 yards north of the Burkittsville Road. They ceased fire and reloaded. The time was 5:20pm and the light was fading away. Without consulting Slocum, they ordered their men forward at the double-quick. The 96th Pennsylvania, at the extreme right, had the worst terrain to cross, ending with a cornfield. When they came out of the cornfield, they were barely 20 paces from the Confederate line. They were hit with a massive volley from the Confederates at the wall. The entire line went to the ground either hit or attempting to duck the spray of lead, but they quickly got up and advanced to the wall, sending the Rebels up the hill. (Clemmons, 2002, p. 305)
Slocum's Division advanced up the eastern side of the mountain and down the western side, stopping at the base. The 4th Vermont proceeded one half mile south along the crest of the mountian and captured the battle flag of the 16th VA, and then proceeded to the western side of the mountain, camping at the base by Slocum's men. The 2nd VT went straight over the mountain to the western side. Hancock's brigade, held in resrve, stayed on the eastern side of the mountain. "The Union pursuit was halted by darkness, the weariness of the men, and the dislocation of the commands, consequent upon the broken character of the field." (Clemmons, 2002, p. 309)
Results of the Union victory included the capture of 600 prisoners, 700 stands of arms, one artillery piece, and four colors at a cost of 113 killed, 418 wounded, and two missing. The Confederates had 70 killed, 289 wounded, and 602 missing. (Clemmons, 2002, pp. 310-312)
Battle of South Mountain Scientist Page. (May). Retrieved May 28, 2016, from http://kms.kapalama.ksbe.edu/projects/2002/civilwar/battle12/scientist.html
Clemens, T. G. (2002). Ezra Ayres Carman and the Maryland Campaign of September 1862 (Vol. 1). New York, NY: Savas Beatie LLC.
Hartwig, D. S. (n.d.). The Maryland Campaign of 1862. Retrieved May 28, 2016, from http://www.civilwar.org/battlefields/antietam/history/the-maryland-campaign-of-1862.html?referrer=https://www.google.com/
Hoptak, J. D. (2011). The Battle of South Mountain. Charleston, SC: The History Press.