On July 21, McDowell, attacked the Confederates near the stone bridge over Bull Run and drove them back to the Henry House Hill. Confederate Gen. Thomas J. Jackson standing like a stone wall, checked the Union advance. With the arrival of Gen. E. Kirby Smith's brigade, the tide turned against the Union forces.
The poorly trained Union volunteers retreated along roads jammed by panicked civilians who had turned out in their Sunday finery to watch the battle. The retreat quickly became a rout.