South Mountain - Crampton's Gap - Sept 14, 1862 - 5:30pm-6:00pm (April 2019)
American Battlefield Trust’s map of the Battle of South Mountain - Crampton’s Gap
When Gen. George B. McClellan was given a mislaid copy of Lee's Special Order 191, the Union army commander knew that portion of Robert E. Lee's divided army was vulnerable to attack and ordered his troops toward South Mountain. At the same time, "Little Mac" sent the Sixth Corps under Gen. William B. Franklin south toward Crampton's Gap with orders to pass over South Mountain and relieve the besieged garrison at Harpers Ferry.
Though only a patchwork force of roughly one thousand Confederates held Crampton's Gap, the excessively cautious Franklin was convinced the Rebels were in strong enough force to delay the advance of his 12,000-man corps. Gen. Henry W. Slocum, however, felt differently. At around 4 p.m., Slocum's division of Maine, New Jersey, New York, and Pennsylvania troops charged headlong up the slope and into Crampton's Gap, dislodging the outnumbered Confederates from the protection of a stone fence. Even the arrival of two Georgia regiments under Howell Cobb, did little to stem the Union tide. Reinforced by a brigade of Vermonters, the Federals made a second attack and drove the remaining Confederates down the western slope of South Mountain, leaving the Sixth Corps in possession of Crampton's Gap. But with daylight fading and Confederate reinforcements forming in the distance, Franklin halted his column for the night.