Bull Run, Antietam and How Warfare Changed Forever

The battle of Manassas showed the Federals that they were in for more than they had bargained for. Thinking that they would be able to simply swat the rebels from the field and end the rebellion, the Confederate fighting ability shocked the Federals, which ultimately ended in their rout and withdrawal to the safety of Washington. They did this without Confederate pursuit—possibly a missed opportunity for the South, but caused primarily by their own inexperience and fatigue.

            At Antietam, the Federals approached the battle more cautiously (as they, under McClellan were now prone to do), because they knew of the Army of Northern Virginia’s fighting ability from very personal experience. With the discovery of the “lost order”, the Federals certainly had the advantage (in both intelligence and force strength), but still lacked the aggressiveness to beat the Confederates, then pursue and destroy them. As in the missed opportunity of the Confederates to pursue the Federals at Manassas, the Federals at Antietam did not pursue due to their own fatigue. However, unlike the Confederates, the Federals did not lack the experience—they had the experience, but lacked the aggressive commander. 

            By the time the two armies reached Antietam, the anticipated “glory of battle” that soldiers had felt before Manassas had passed. Soldiers now did their duty fighting bravely for both sides, but they also carried the year of experience into the battle, which caused both sides to approach combat more cautiously. Massed formations still made frontal assaults when necessary, but used skirmishes and defensive cover whenever possible to protect troops from the intense firepower. Bloody Lane and the attacks across Burnside Bridge are two examples of this.