The First Battle of Bull Run, called the Battle of First Manassas by Confederate forces, was the first major battle of the American Civil War. The battle was fought on July 21, 1861, in Prince William County, Virginia, just north of what is now the city of Manassas and about thirty miles west-southwest of Washington, D.C. The Union army was slow in positioning themselves, allowing Confederate reinforcements time to arrive by rail. Each side had about 18,000 poorly trained and poorly led troops. The battle was a Confederate victory and was followed by a disorganized post-battle retreat of the Union forces.
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 was expected to bring an early end to the Confederacy. Yielding to political pressure, Brigadier General Irvin McDowell led his unseasoned Union army across Bull Run against the equally inexperienced Confederate Army of Brigadier General P. G. T. Beauregard, whose forces were camped near Manassas Junction. McDowell's ambitious plan for a surprise flank attack on the Confederate left was poorly executed although the Confederates, who had been planning to attack the Union left flank, found themselves at an initial disadvantage.
