The First Battle of Bull Run, also known as the First Battle of Manassas, was the first major battle of the American Civil War. It took place on July 21, 1861, in Prince William County, Virginia, about 30 miles (48 km) southwest of Washington, D.C. The Union Army, commanded by Brigadier General Irvin McDowell, launched an offensive against the Confederate Army, commanded by General P.G.T. Beauregard, in an attempt to capture the Confederate capital of Richmond, Virginia. The battle ended in a Confederate victory, marking the first major defeat for the Union Army.