Harpers Ferry in No Shape to Defend Itself; McClellan Clueless to Many Things

September 12, 1862 (Friday)

General John Wool

General John Wool had lost track of his men. The Union commander of the Middle Department, comprising Pennsylvania, New Jersey and the Maryland counties along the B&O Railroad, was headquartered in Baltimore, while his troops in Harpers Ferry were quickly being surrounded by invading Confederate forces.

“You can put any of my troops under McClellan’s command,” wrote Wool to General-in-Chief Henry Halleck. The problem was, Wool had no real idea how many troops he had. He speculated that Harpers Ferry had seven or eight thousand. McClellan, who had already asked Halleck for the use of the Harpers Ferry garrison, supposed their number to be closer to 25,000. In truth, it was around 14,000, but as the sun rose over South Mountain and Maryland Heights, just east of the town, it didn’t really matter.1

Commanding the troops in question was General Dixon Miles, a career military officer pushing sixty. Miles had been first ignorant and then unreasonably optimistic over the reports of Rebels approaching Maryland Heights. He estimated only ten regiments opposed him. In truth, there were nearly ten times that number closing in around him.

“I expect this will be the last you hear of me until this affair is over,” wrote Miles to Halleck. “All are cheerful and hopeful. Good-bye.”2

General Miles had reason to be hopeful. He believed only two brigades of infantry and some artillery were approaching him. His force, perhaps double that figure, could hold off such a raid.

What Miles failed to notice was Stonewall Jackson’s force to the north, 12,000-strong. He also never noticed General John Walker’s 3,400 men approaching Louden Heights to the south. And though he allowed that a few more regiments of Rebels had joined the ten regiments after dusk, he had no idea that they were actually joined by six other brigades under Lafayette McLaws.

Jackson was just entering the abandoned Martinsburg to the north, and Walker was about to ascend Louden Heights as McLaws made his move. As his division drew closer, he peeled off brigades to close Solomon’s, Brownsville, and Crampton’s Gaps. Another plunged toward the Potomac, hitting Point of Rocks. Each sealed off any possible Federal escape route towards Washington.

The main Confederate thrust came from Kershaws Brigade, stumbling its way across the crest of Elk Ridge. When they approached the thin Union lines atop Maryland Heights – an extension of the ridge – they met with equally thin resistance. Greeting them were the greenest of troops, having been in blue for barely three weeks. Most of Miles’ men were in the town itself.

General Kershaw

Though unexperienced, their fortifications and a handful of reinforcements (bringing their number to around 1,700 men), was enough to keep Kershaw too unsure to commit his roughly 2,000 veterans.3

General Lee’s Special Order 191 required directed McLaws to be upon Maryland Heights, which he had technically accomplished. For Walker, he was to be upon Louden Heights, “if practicable.” By nightfall, he was at Hillsborough, and ready to move the next morning for the Heights. Jackson, though remembered as running a day behind, was actually just where the Order required him to be. On the morning of September 12, he was supposed to “take possession of the Baltimore and Ohio Railroad, capture such of them as may be at Martinsburg.”4

Before noon, this was accomplished. He sent A.P. Hill’s Division ahead, towards Harpers Ferry. The rest of his command would follow the next day.

General George McClellan, commanding Army of the Potomac, believed the Rebel army of General Lee might be slipping away, to recross the Potomac River back into Virginia. “From all I can gather,” he wrote his wife this afternoon,” secesh is skedaddelling & I don’t think I can catch him unless he is really moving into Penna [….] I begin to think that he is making off to get out of the scrape by recrossing the river at Williamsport.”5

More or less, however, he knew the approximate route that General Lee had taken. The enemy was “moving in two directions. Viz. on the Hagerstown and Harpers Ferry roads.”6

As the day wore on and his men marched into Frederick, occupying the former camps of Lee’s Army of Northern Virginia, McClellan began to think of Harpers Ferry. He had heard no firing from that direction, and assumed all to be well enough. Due to Miles’ last dispatch, he knew that the Rebels were closing in, but figured that the garrison “if they fight at all,” could hold out until he could relieve them.7

General Ambrose Burnside

General Ambrose Burnside commanded the right wing of McClellan’s Army of the Potomac. His cavalry had been skirmishing with their Rebel counterparts all day. From the intelligence he could gather, he believed that Lee was headed into Pennsylvania (which was actually Lee’s ultimate goal). From McClellan, he heard that the Rebels were moving towards Harpers Ferry and upon Gettysburg, but doubted that.

“I can hardly understand how they can be moving on these two latter roads at the same time,” wrote Burnside to Halleck. “If they are going into Pennsylvania they would hardly be moving upon the Harper’s Ferry road, and if they are going to recross, how could they he moving upon Gettysburg!”

Of course, that was precisely what the Confederates were doing, though they had no intension of recrossing and staying in Virginia.

General Hooker, commanding a corps under Burnside, put it more bluntly: “It is satisfactory to my mind that the rebels have no more intention of going to Harrisburg than they have of going to heaven.”8

Whether the Rebels were moving farther northward into Pennsylvania or returning to Virginia, nobody seemed to have a clue. Soon, however, that would all change.



  1. Official Records, Series 1, Vol. 19, Part 2, p275, 268. []
  2. Official Records, Series 1, Vol. 50, Part 1, p819. []
  3. Official Records, Series 1, Vol. 19, Part 1, p862-863. []
  4. Official Records, Series 1, Vol. 19, Part 2, p603-604. []
  5. Letter from George McClellan to Mary Ellen McClellan, September 12, 1862. As appearing in The Civil War Papers of George B. McClellan edited by Stephen W. Sears, Da Capo Press, 1989. []
  6. Official Records, Series 1, Vol. 19, Part 2, p270-271. []
  7. Official Records, Series 1, Vol. 19, Part 2, p254, 272. []
  8. Official Records, Series 1, Vol. 19, Part 2, p273-274. []
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Harpers Ferry in No Shape to Defend Itself; McClellan Clueless to Many Things by Eric is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported