Civil War Wiki
Battle of Crampton's Gap
Part of the American Civil War
Date September 14, 1862 (1862-09-14)
Location Maryland, United States
Result Union victory
United States of America Confederate States of America
William B. Franklin Howell Cobb
12,800 2,100
Casualties and losses
533 total (US) 887 total (CS)

The Battle of Crampton's Gap was a battle fought between forces under Confederate Brig. Gen. Howell Cobb and Union Maj. Gen. William B. Franklin as part of the Battle of South Mountain on September 14, 1862, at Crampton's Gap in Central Maryland.

Franklin's VI Corps attacked a small, hastily assembled Confederate force at Crampton's Gap in South Mountain to protect the rear of Maj. Gen. Lafayette McLaws, who was across Pleasant Valley on Maryland Heights taking part in the siege of Harpers Ferry. Despite inferior numbers, the Confederate force held out throughout the day, taking heavy casualties. By the evening the VI Corps broke the Confederate line and proceeded through the gap into Pleasant Valley. Franklin, however, failed to follow up on his success and did not attack McLaws on Maryland Heights.

Tactically the battle resulted in a Union victory because they broke the Confederate line and drove through the gap. Strategically, the Confederates were successful in stalling the Union advance and were able to protect McLaws's rear.


On September 13, 1862, Union Maj. Gen. George B. McClellan received a lost copy of Robert E. Lee's Special Order No. 191, which detailed the Confederate plan of action in Maryland, including the fact that Lee had divided his army and sent a portion to capture Harpers Ferry.

As part of that siege, units under Maj. Gen. Lafayette McLaws were sent to take Maryland Heights and then bombard the Union garrison in the town. To protect his rear flank, McLaws stationed a small guard at Brownsville Gap (a smaller gap a few miles south of Crampton's Gap) and Crampton's Gap, both of which allowed access to Pleasant Valley and the eastern slope of Maryland Heights. The force at Crampton's Gap consisted of one battery of artillery, 3 regiments of infantry under Brig. Gen. William Mahone, one brigade under Brig. Gen. Howell Cobb, and a small cavalry detachment under Col. Thomas T. Munford.

McClellan ordered Maj. Gen. William Franklin and his VI Corps to set out for Burkittsville from his camp at Buckeystown the following morning at daybreak, with instructions to drive through Crampton's Gap and attack McLaws's rear. Although he sent the order immediately, by allowing Franklin to wait until morning to depart, his order resulted in a delay of nearly 11 hours.


The small Confederate force used the terrain to its maximum advantage with Munford's cavalrymen initially stationed at the eastern base of the mountain, the artillery halfway up its slope, and the infantry entrenched at the summit. From their vantage point on the mountain they watched throughout the morning as Franklin's VI Corps marched across the Middletown Valley towards them.

When the Federals reached Burkittsville around noon, the Confederate artillery opened up. In Burkittsville, while under artillery fire, Franklin assembled his troops into three columns. At 3 p.m., after a delay of nearly 3 hours, the VI Corps finally began its assault. The reason for the delay has never been ascertained, but it would prove costly. The Union advance was slow and steady, supported by artillery. Their superior numbers quickly overwhelmed the cavalry and artillery on the slopes of the mountain. The retreating Confederates were briefly rallied at the summit by General Cobb, but the weight of the Federal advance was too much. Once the VI Corps reached the summit they drove the Confederates from their positions, inflicting heavy casualties, in just 15 minutes of fighting.

After the Confederate line at the summit broke, the troops scattered in all direction into Pleasant Valley and were thereafter totally unable give any further fight to the Federals. However, they had held out for three hours, which, in concert with the delay of the VI Corps getting to and beginning the attack on Crampton's Gap, meant that it was after 6:00 p.m. when Franklin reassembled his men in Pleasant Valley and too late to begin a second attack on McLaws's force on Maryland Heights. The following day Harpers Ferry surrendered to the Confederates, while Franklin sat camped in Pleasant Valley, now convinced he was outnumbered by McLaws by nearly two to one.


In total, the VI Corps suffered 115 killed, 416 wounded, and 2 missing, for a total of 533 casualties. The Confederate forces suffered 130 killed and 759 wounded, for a total of 887 casualties.

Tactically, the Federals were successful in driving the Confederates from the gap, the first time any portion of Lee's army had been driven from the field up until this point in the war, and were able to inflict heavy casualties in doing so. Strategically, the Confederate force was able to stall the Federal advance for three hours despite being outnumbered nearly six to one. The delay was long enough to ensure the safety of McLaws on Maryland Heights and capture of Harpers Ferry the following morning.

More significantly, after seizing Crampton's Gap, General Franklin failed to attack McLaws and allowed Stonewall Jackson's Corps to reunite with the main body of the Confederate army at Sharpsburg without a fight. There Lee hastily stood his ground in the Battle of Antietam, the war's bloodiest day. President Abraham Lincoln then used the marginal Union victory at Antietam as a springboard to his Emancipation Proclamation which changed war aims. The actions of Franklin at Crampton's Gap thus set the stage for Antietam three days later.


nl:Slag bij Crampton's Gap