Civil War Daily Gazette

A Day-By-Day Accounting of the Conflict, 150 Years Later

The Battles of South Mountain: The Day Has Gone Against Us

September 14, 1862 (Sunday)

It was the Lord’s Day. In towns across the nation, church bells were ringing, calling believers to worship. Hymnals were opened and songs were sung, echoing through valleys, city streets, from atop hills, and over sparkling late summer streams. In thousands of villages, voices were raised and heads were bowed in reverence. Except here, along South Mountain in northern Maryland.

General Jacob Cox

Captain Charles Russell of the 1st Maryland Cavalry, along with nine other Union troopers, had picked their way from besieged Harpers Ferry, through Confederate lines, until they finally crossed South Mountain and found General Jesse Reno, commanding the IX Corps of the Army of the Potomac. Dawn was just breaking when he delivered the news that the Federal garrison at Harpers Ferry could hold out for only two more days.

Reno gave Russell a fresh horse and sent him along to General McClellan’s headquarters in Frederick. McClellan was surprised to learn that Col. Dixon Miles, commanding the Union troops at the Ferry had abandoned the much more defensible heights surrounding the town. All was not lost, however, as McClellan had already sent General William Franklin’s Corps to rescue the garrison. McClellan gave Russell a note and sent him along to hurry Franklin forward.

It would take Captain Russell five hours to reach Franklin, who was, by then, engaged in a pitched battle just west of Burkittsville.1

South Mountain (during the battle).

McClellan’s orders for Franklin were simple (though fairly impossible). He was to “cut off, destroy or capture [Confederate General Lafayette] McLaws’ command & relieve Col. Miles” at Harpers Ferry. Once accomplished, he was to head northeast to cut off the main Confederate army’s line of retreat. McClellan wanted to “cut the enemy in two and beat him in detail.”2

The orders for the rest of the army, however, were muddled. He believed that all of the Rebels not around Harpers Ferry were in Boonsboro. He was mistaken. Between his lead troops and Boonsboro was South Mountain. Two passes led over the range – Turner’s Gap to the north and Fox’s Gap to the south. They might be guarded, he thought, but not defended.

When the Blair Witch Project was big, this sign was stolen a LOT.

At dawn, a single brigade and a cavalry probe headed towards Turner’s Gap under the direction of General Jacob Cox. Along the way, he heard from a paroled Union prisoner that the Gap before them was indeed defended. Cox then decided to outflank the Rebels by using Fox’s Gap. When he marched there, however, he found that also heavily defended. Around 9am, the fighting turned heavy and then vicious, as the adversaries fixed bayonets. In hand-to-hand melee, they charged and countercharged across fields and meadows, through thickets and woods. Cox’s men, mostly from Ohio, overpowered the unexpected Confederates, commanded by D.H. Hill, holding Fox’s Gap. The fight, however, was far from over.3

During the lull that ensued after Cox drove the Rebels from Fox’s Gap, General James Longstreet, commanding the Confederates in Hagerstown and Boonsboro, hurried back reinforcements to hold South Mountain. Cox, on the other hand, waited for reinforcements of his own. In the early afternoon, General Ambrose Burnside, commanding the Union right wing (I and IX Corps) finally showed up. With him came a brigade of reinforcements for Cox, but wanted to wait until the I Corps could be put into position so that Tuner’s Gap and Fox’s Gap could be assailed simultaneously. Around 3:30 in the afternoon, all was ready. Burnside had arrayed his 28,000 men against roughly 10,000 Rebels.4

Around the same time that Burnside finally let loose his troops, General Franklin at Crampton’s Gap near Burkittsville was in the thick of it with his 12,000 men.

When heading west from the usually quaint village of Burkittsville, Maryland, the traveler finds a main road through a passage named Crampton’s Gap. A few miles to the south was the lesser-used Brownsville Gap. Confederate General McLaws had placed a small force of 1,000 or so to guard the passes, while the rest of his force assaulted Harpers Ferry.

Franklin had arrived in town at noon, but took an inexplicable three hours to ready his men for battle. During that time, the Confederates were able to double their numbers while watching the blue lines grow longer. Much of the time was spent by Franklin trying to suss out the enemy position.5

Battle of Crampton's Gap

Franklin received a dispatch from McClellan around 2pm that left him an out. While he was ordered to “carry Burkittsville at any cost” (which he already held), he was also instructed that if he found the Rebels “in too great a force at the pass let me know at once, and amuse them as best you can so as to retain them there.” McClellan then promised to throw the rest of the Army of the Potomac upon Crampton’s Gap.6

Unsure of what was before him, he cautiously advanced his troops while the artillery boomed overhead. Within minutes, the troops were fully engaged. The smoke of battle clung in the dense forests and, with the sun dipping behind South Mountain, Franklin could no longer see the action.7

East of South Mountain - where the Federals formed up.

After an hour of fighting, he reported back to General McClellan that Crampton’s Gap was too heavily defended to carry without reinforcements.8 But Franklin was merely being pessimistic. His troops, their dander already up, carried Crampton’s Gap.

While the fighting developed at Crampton’s it raged with a relentless fury at Fox’s and Turner’s. As Longstreet’s reinforcements came up, filing into Fox’s Gap, they attacked, throwing the Federals under Jesse Reno back on their heels. The Confederates attempted to flank the Union left, but quick thinking by General Cox stymied their advance.9

Ambrose Burnside, commanding the Federals at both gaps, then ordered a general assault. On the Union right, just north of Turner’s Gap, General Joe Hooker’s I Corps hit the Rebels hard. But they held their ground against overwhelming numbers and managed a counterattack before being smashed by a Federal volley. Hooker’s men advanced and drove the Rebels back, taking the contested high ground.

While Cox’s men at Fox’s Gap and Hooker’s north of Turner’s Gap were engaged, Burnside threw the Iron Brigade, commanded by John Gibbon, up the National Road to Turner’s Gap itself. There, the Rebels stuck and Gibbon could do little more than hold his ground, while his men fired away at the enemy.10

Back at Fox’s Gap, with light growing dim, General Jesse Reno was trying to figure out why his IX Corps wasn’t following up their victory by chasing the retreating Rebels. There seemed to be a lull that fell over the field, but soon, Reno heard Confederate troops advancing on his front. He called up a regiment to throw forward skirmishers.

As they advanced, Reno squinted through field glasses towards a darkened tree line, trying to determine if the Rebels were actually there. Then, piercing the dim air, muzzles flashed and General Reno fell to the ground, several bullets tearing through his chest.

The field where Reno was mortally wounded.

A stretcher was quickly found and he was taken to the foot of the mountain. “Hello Sam,” said the weakened Jesse Reno to his friend, General Samuel Sturgis – they had graduated West Point together. “I’m dead.”

“Oh no, General. Not as bad as that, I hope,” replied General Sturgis.

“Yes, yes. It is all up with me. I am dead. Good-bye.” And the life left the body of Jesse Reno.11

Though Crampton’s Gap and Fox’s Gap had fallen, the Confederates still held Turner’s Gap. But General Lee knew they had to leave. This sudden attack was out of character for General McClellan. What Lee, of course, did not know was that McClellan learned of Lee’s plans for the campaign with the capture of Special Orders No. 191.

General Jesse Reno

With his army scattered across the countryside, Lee realized that he would have to abandon his strike into the heart of Pennsylvania. That night, General Lee sent a dispatch to General McLaws, surrounding Harpers Ferry.

“The day has gone against us and this army will go by Sharpsburg and cross the river.”12

Though the day was not his, the battles at South Mountain gave Lee twenty-four hours to gather his army. Had the Gaps not been held, McClellan might have fallen upon Lee’s divided command.

The casualties: At Turner’s Gap, the Federals lost 933, while at Fox’s Gap, they lost 858. At Crampton’s Gap, the Federals lost 538. The Confederates never tallied their dead, but it’s assumed they lost roughly 2,300 at Turner’s and Fox’s Gaps, and, perhaps 1,000 at Crampton’s.13



  1. Official Records, Series 1, vol. 19, Part 1, p720-721. []
  2. Official Records, Series 1, Vol. 19, Part 1, p46. []
  3. “Forcing Fox’s Gap and Turner’s Gap” by Jacob Cox, as appearing in Battles & Leaders Vol. 2, The Century Co., 1912. []
  4. “The Battle of South Mountain or Boonsboro” by D.H. Hill, as appearing in Battles & Leaders Vol. 2, The Century Co., 1912. []
  5. Landscape Turned Red by Stephen W. Sears, Mariner Books, 1983. []
  6. Franklin to McClellan in The Civil War Papers of George B. McClellan edited by Stephen W. Sears, Da Capo Press, 1992. []
  7. From First to Last: The Life of Major General William B. Franklin by Mark A. Snell, Fordham Univ Press, 2002. []
  8. Footnote on page 460 of The Civil War Papers of George B. McClellan edited by Stephen W. Sears, Da Capo Press, 1992. []
  9. “Forcing Fox’s Gap and Turner’s Gap” by Jacob Cox, as appearing in Battles & Leaders Vol. 2, The Century Co., 1912. []
  10. Landscape Turned Red by Stephen W. Sears, Mariner Books, 1983. []
  11. The Class of 1846: From West Point to Appomattox by John C. Waugh, Random House, 1999. []
  12. Official Records, Series 1, Vol. 51, Part 2, p618. []
  13. Federal figures from Official Records, Series 1, Vol. 19, Part 1, p187. Confederate estimates from Landscape Turned Red by Stephen Sears, Mariner, 1983. []
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