The Battle of Bull Run began with a night march by a number of regiments from the federal right flank. They moved north-by-northwest and encountered more difficulty than expected. Not only were the men tired and foot-sore, but they collided with the equipment wagons, often jostling each other to see who could remain on the road. In the tiny hamlet of Centerville, thousands of federal men collided, with no one understanding who had priority in the advance. Even so, daylight found thousands of federal troops on the west side of the Bull Run, executing the flanking maneuver that McDowell had planned.

The first firing began just before dawn and increased rapidly from that moment. The Confederates, especially those on their left flank, were astonished to find the Federals so close, and a few artillery salvoes drove them into a dignified retreat. To this point, McDowell’s plan was coming along nicely.