On July 21, 1861, the First Battle of Bull Run was fought. It was the first real conflict of the Civil War. The Union army, commanded by General McDowell, consisted of 28,000 men and they opposed the 33,000 Confederate troops led by General Beauregard.

The battle lasted for five hours and despite heavy losses on both sides, neither army was a clear victor. However, this battle did prove that this was not going to be a one-sided war for either side, as had been predicted.