On 29 May, 1861, Irvin McDowell was given command of the Army of the
Potomac, which consisted of about 30,000 men, who, with the exception of 700 or
800 regulars, were almost entirely raw recruits. With these troops, in response
to the public demand for some immediate action, he was ordered, on 16 July, to
march against the Confederate army, posted at Manassas Junction under General
Beauregard. His plan of campaign had been carefully studied out, and its
principal feature was to turn the enemy's left flank while threatening the
front, which was well posted behind Bull Run on an elevation that commanded the
entire plateau. A preliminary action, without the authority of General McDowell,
took place at Blackburn's Ford on the lath, and developed the fact that the
Confederates were strongly entrenched.
The National troops, unable to carry the masked batteries, fell back to
Centreville, where they rested during the two following days. On the morning of
the 21st the National army crossed the run and succeeded in throwing the enemy's
left into such confusion that the presence of Generals Beauregard and Johnston
was necessary to rally their troops, who then re-formed in line on the crest of
the hill. A severe struggle for this position ensued, and it was lost and won
three times, and about three o'clock in the afternoon it remained in the control
of the National forces. But soon after that hour fresh Confederate
re-enforcements arrived and completely turned the tide of battle. McDowell's
men, who had been on their feet since two o'clock in the morning, who had
marched twelve miles to the field and been engaged in heavy fighting since ten
o'clock, were now exhausted by fatigue and want of food and water. Unable to
withstand the fierce attack of fresh troops, they broke and retired in confusion
down the hillside and made a disorderly retreat to Washington. Thus the first
great battle of the civil war was fought and lost.
According to General Sherman, "it was one of the best-planned
battles, but one of the worst fought." Heavy losses of artillery and
other war-supplies were experienced as the soldiers fell back on the capital.
Both armies were fairly defeated, and whichever had stood fast the other would
have run. General Johnston says: "The Confederate army was more
disorganized by victory than that of the United States by defeat."