LEE INVADES MARYLANDOrdered by President Lincoln “to
destroy the rebel army,” McClellan led
a revitalized 70,000-strong force out of
Washington in pursuit of Lee.
Union luck
On September 13,
McClellan’s troops
entered Frederick,
recently vacated
by the Army of
Northern Virginia.
McClellan then
enjoyed a stroke of
luck. A copy of Lee’s Special Order 191,
circulated to all the Confederate
commanders on September 9, was
found in a field outside the town and
passed to McClellan’s staff. It gave full
details of the location of Lee’s forces.
McClellan was exultant, declaring:
“Here is a paper with which if I cannot
whip Bobbie Lee, I will be willing to go
home.” On the night of September 13,
Union forces moved toward South
Mountain. Once through the passes
they would be able
to attack Lee’s
army before it
could concentrate
or escape. While
Longstreet
marched back
from Hagerstown,
the Confederate defenses at the
mountain passes were lightly held.
Fighting raged through September 14.
Crampton’s Gap fell after hours of
resistance by a handful of Confederates
faced with 12,000 Union troops, butUnion loss at Harpers Ferry
The Confederate seizure of the Union armory
at Harpers Ferry on September 15, 1862 left the
railroad bridge in ruins and a valuable haul of war
supplies in Confederate hands.
AFTER
this was exploited too late. Turner’s
Gap and Fox’s Gap were held by D. H.
Hill’s division throughout the day. The
delay that this imposed on McClellan’s
army was enough to allow Lee to
escape. On September 15, McClellan
ordered his troops to retreat to the
town of Sharpsburg, between Antietam
Creek and the Potomac.Taking Harpers Ferry
Meanwhile, Jackson was threatening
Harpers Ferry. The arsenal was guarded
by 11,000 green Union troops under
Colonel Dixon Miles. Holding the high
ground, the Confederates sited their
artillery and attacked at will. Harpers
Ferry surrendered on September 15.
Jackson seized military stores as well
as 11,000 prisoners. Leaving MajorThe number
of soldiers that
General McClellan estimated Lee had in
his army during the Maryland campaign.
The actual number of Confederate troops
never exceeded around 55,000.120,000
General A. P. Hill’s men in charge,
Jackson joined Lee at Sharpsburg. He
arrived on September 16 to find Lee
facing McClellan’s army across
Antietam Creek. All day the opposing
artillery batteries had been dueling.
Darkness brought the additional rattle
of heavy skirmishing up and down the
lines, a prelude to impending battle.Lee’s decision to fight at Sharpsburg
132–33 ❯❯, rather than withdraw across
the Potomac into Virginia, showed a
confidence in his troops’ superior ability.LEE RALLIES
Although Lee was buoyed by news of Jackson’s
success at Harpers Ferry, he was also unwilling
to accept that his Maryland campaign had
failed. McClellan, meanwhile, proceeded with
his habitual caution. On September 15, his Army
of the Potomac had begun arriving at Antietam
Creek, but left Lee undisturbed on the
opposite bank. The next day, McClellan had
some 60,000 men facing 25,000 Confederates.
By September 17 he was ready, but Lee had
amassed most of his men, so the chance of
a decisive Union victory was missed.GEORGE BRINTON MCCLELLAN