Bull Run was the first full-scale battle of the Civil War. The fierce fight there forced both the North and South to face the sobering reality that the war would be long and bloody.

How it ended
Confederate victory. After this stinging defeat for the Union, Brig. Gen. Irvin McDowell, the commander of the Union Army of Northeastern Virginia, was relieved and replaced by Maj. Gen. George B. McClellan, who set about reorganizing and training what would become the Army of the Potomac.