Battle of South Mountain
Following his triumph at Second Manassas, Gen. Robert E. Lee invaded Maryland for two specific reasons: to relieve Virginia of the burden of feeding his Army of Northern Virginia, and with the hope of earning diplomatic recognition from Great Britain and France, thereby establishing Southern independence. While encamped at Frederick, MD, a copy of Lee’s Special Orders No. 191 was inadvertently left behind and fell into the hands of his adversary, Gen. George B. McClellan, commanding the Army of the Potomac. The famous “Lost Order” revealed Lee’s campaign plans, providing McClellan a rare opportunity commanders only dream about.
As the Confederate army moved westward to Boonsboro, McClellan’s counter strategy unfolded in the Middletown Valley. To employ a boxing metaphor, McClellan’s strong right arm relentlessly pounded Lee’s rearguard at South Mountain (Turner's and Fox's Gaps) while his left, G. William B. Franklin’s Sixth Army Corps (12,800), administered the coup de main at Crampton’s Gap six miles to the south, back door to Harpers Ferry then under siege by Gen. “Stonewall” Jackson. This latter stroke implemented McClellan’s mandate to “divide the enemy in two and beat him in detail.” By driving a wedge between the widely separated halves of Lee’s army, Confederate forces could be confronted at numerical disadvantage leading to a probable close to field operations east of the Appalachians and perhaps and early end to the war. Here is the stuff of which high drama is made.
McClellan ordered Franklin to cross the Middletown Valley, to push through Crampton’s Gap on South Mountain and relieve the Harpers Ferry garrison from which point he could advance against either half of Lee’s forces as required. Instead of marching immediately after receipt of these orders on the 13th, Franklin bedded his men down for the night, pursuing his route first thing on the morning of September 14.
The Sixth Corps arrived in Burkittsville at noon and was allowed to prepare a midday meal while Franklin and his subordinates debated on which side of the town to attack. Columns of assault were formed north of town at 4 p.m., met by the Virginia brigade of Col. William A. Parham (800) at the mountain’s base. Col. Thomas T. Munford was in overall command. A fire fight ensued for over an hour. Parham was reinforced at 5:30 by Gen. Howell Cobb’s brigade (1,300) which arrived just as the Virginians gave way to the main attack by Union Gen. Henry Slocum’s division. As Parham precipitately retreated, Cobb’s men were trapped on three sides by six times their number - the brigades of Bartlett, Newton and Torbert - and were forced back into the gap for a showdown. The last stand in the gap dissolved at twilight, the Confederates retreating to Brownsville in Pleasant Valley.
On the 15th, a Confederate battle line was thrown across Pleasant Valley in a desperate attempt to confront Franklin’s victorious forces. Franklin however did not attack after learning that Harpers Ferry had surrendered that morning. No effort was made to harass the Confederates that day or the next, allowing time to reduce Harpers Ferry and to evacuate the remaining Confederates from Pleasant Valley. On the morning of the 17th, Franklin was ordered to join McClellan at Sharpsburg where the Battle of Antietam occurred in all its fury.
After receiving news of the outcome at Crampton’s Gap and South Mountain, Lee reluctantly decided to abandon Maryland, but the fall of Harpers Ferry encouraged him to stay and confront McClellan in pitched battle at Sharpsburg, a tactical draw. In reviewing Franklin’s delay and inactivity at Crampton’s Gap - the first complete victory over any portion of Lee’s forces to date - we consider one of the great might-have-beens of the War Between the States, defining the pivotal fulcrum of the Maryland Campaign of 1862.