Following his brilliant victory at the Second Battle of Bull Run two days earlier, Confederate General Robert E. Lee strikes retreating Union forces at Chantilly, Virginia, and drives them away in the middle of an intense thunderstorm.
Although his army routed the Yankee forces of General John Pope at Bull Run, Lee was not satisfied. By attacking the retreating Federals, Lee hoped to push them back into Washington, D.C., and achieve a decisive victory by destroying the Union army. The Bull Run battlefield lay 25 miles east of the capital, allowing Lee room to send General Thomas J. "Stonewall" Jackson's corps on a quick march to cut off part of the Union retreat before reaching the defenses of the capital.
Jackson departed with his corps on August 31. Using General J.E.B. Stuart's Rebel cavalry as a screen, he swung north and then east toward Washington. Under orders of Union General-in-Chief Henry Halleck, Pope tried to hold the town of Centerville from the advancing Confederates. Jackson moved north around Centerville, placing the bulk of Pope's force in grave danger as the Southerners moved towards Fairfax. By the afternoon of September 1, Pope evacuated Centerville and Jackson pressed to the north of the main Yankee army.
Late in the afternoon, a Union division commanded by General Isaac Stevens attacked Jackson near Chantilly. In a driving rainstorm punctuated by thunder and lightning, Stevens's men drove into the Confederates and scattered a Louisiana brigade. But after Stevens was struck in the head by a Rebel bullet and killed, Jackson's men drove the Union troops back. Another Yankee general, Philip Kearney, was killed when he accidentally rode behind the Confederate line in the storm.
The battle was over within 90 minutes, although the storm persisted. Confederate casualties numbered about 500, while the Union lost 700. Lee could not flank Pope's army, so he turned his army northward for an invasion of Maryland. The result was the Battle of Antietam on September 17.