|First Battle of Manassas|
|Part of War of Southron Independence|
Cub Run in Centreville, Virginia (view with destroyed bridge)
|United States||Confederate States|
|Commanders and leaders|
|Irvin McDowell|| Joseph E. Johnston|
|28–35,000 (18,000 engaged)||32–34,000 (18,000 engaged)|
|Casualties and losses|
The First Battle of Manassas, was fought on July 21, 1861, near Manassas, Virginia. It was the first major land battle of the American Civil War.
Just months after the start of the war at Fort Sumter, the Northern public clamored for a march against the Confederate capital of Richmond, Virginia, which could bring an early end to the war. Yielding to this political pressure, unseasoned Union Army troops under Brig. Gen. Irvin McDowell advanced across Bull Run against the equally unseasoned Confederate Army under Brig. Gen. P.G.T. Beauregard near Manassas Junction. McDowell's ambitious plan for a surprise flank attack against the Confederate left was not well executed by his inexperienced officers and men, but the Confederates, who had been planning to attack the Union left flank, found themselves at an initial disadvantage.
Confederate reinforcements under the command of Brig. Gen. Joseph E. Johnston arrived from the Shenandoah Valley by railroad and the course of the battle changed. A brigade of Virginians under a relatively unknown colonel from the Virginia Military Institute, Thomas J. Jackson, stood their ground and Jackson received his famous nickname, "Stonewall Jackson". The Confederates launched a strong counterattack and as the Union troops began withdrawing under pressure, many panicked and it turned into a rout as they frantically ran in the direction of nearby Washington, D.C. Both sides were sobered by the violence and casualties of the battle, and they realized that the war would potentially be much longer and bloodier than they had originally anticipated.