 Confederate cavalry under Col. Thomas T. Munford surprised and routed the Federal force of Cole's Maryland Cavalry and the independent Loudoun Rangers.The engagement successfully cleared the area of Federal forces, allowing Robert E. Lee and the Army of Northern Virginia to occupy the town two days later on September 4, before crossing the Potomac north of town on September 6.After the failure of Army of Northern Virginia to deliver a decisive blow to the Army of Virginia at the Battle of Ox Hill following the Second Battle of Bull Run, Robert E. Lee decided it unwise to pursue the Federals any further towards their fortifications near Washington D.C..