Union General John Pope, apparently broken by his defeat at
Second Manassas, planned to retreat to the defenses of Washington .
But General Halleck instead
ordered Pope to attack Lee’s forces at Manassas .
But Lee had already begun to move. He
sent Stonewall Jackson’s corps around the Union right flank while Longstreet
stayed in place to deceive Pope. Jackson marched north and east and near the intersection
of modern-day US
50 and US 29. Union cavalry sighted Jackson ’s forces and
alerted Pope, who canceled the attack and began the retreat from
Centreville. On the morning of September
1st, Pope sent two brigades under Isaac Stevens to block Jackson ’s march. Phillip Kearny’s division followed in the
afternoon. Jackson ’s men, exhausted, made camp on Ox
Hill. About 3 p.m., Stevens’ Union
brigades arrived at Ox Hill. Despite
being outnumbered, Stevens immediately attacked across a field towards the
Confederate center. The attack was
initially successful, but a counter-attack by Jubal Early drove them back. General Stevens died during this fight. Kearny arrived
about 5 p.m., along with a raging thunderstorm that soaked ammunition and eliminated
visibility so much that at one point, Kearny
rode into the Confederate line. He
realized his mistake and turned back but was shot and killed. The Union troops then withdrew from the
field. Although tactically inconclusive,
it is counted a southern victory because the battle neutralized any threat from
the Union Army and allowed Lee to begin his Maryland campaign. Pope was fired by Lincoln and replaced by Ambrose Burnside.
Also on September 1st, in Madison County,
Tennessee, Union and Confederate cavalry
clashed at Britton’s Lane. The fight
resulted in a southern victory and helped the larger strategy of trying to keep
Grant from reinforcing Buell in Tennessee .
On September 2nd, southern forces under Kirby
Smith began their invasion of Kentucky . Two days later, they captured the state
capital Frankfurt .
Robert E. Lee led the Army of Northern Virginia into Maryland on September 5th, taking Frederick on the 6th. As they moved north, the southern troops
destroyed the Baltimore and Ohio
railroad bridge over the Monocacy
River .
On September 9th, Lee drafted Special Order 191,
which described how he would divide the army, and what routes they would take
into Maryland . That same day Samuel Heintzelman takes
command of the defenses on the south side of Washington .
The Battle of Harpers Ferry was fought from September
12-15. Jackson attacked the town, location of the
Federal Arsenal, from three sides. The
Union commander, Dixon Miles, although knowing of Jackson ’s approach, declined to post troops
to the strategically important heights surrounding the town. When Jackson ’s
forces arrived, they set up artillery on the heights and began a systematic bombardment
of the town. Miles realized that his
situation was hopeless and surrendered, making more than 12,000 Union soldiers prisoners.




