Following the Battle of Ball's Bluff on October 21, major offensive action was halted in the eastern theater, as both armies went into winter quarters.

Such was the case early on the morning of December 20 when General Stuart, with a mixed brigade of infantry comprising the regiments of the 6th South Carolina, 1st Kentucky, 10th Alabama, and 11th Virginia, 150 of his cavalry troopers and Allen S. Cutts's four-gun Georgia battery, set out north from their position near Centreville to escort the army's wagons trains on a foraging expedition into Loudoun County.

Meanwhile, General Ord, leading the 10,000 strong 3rd Brigade of Pennsylvania Reserves set out west from Langley to clear the south bank of the Potomac River of Confederate pickets and partisans in Fairfax and Loudoun.

Commander: Brigadier General Edward O. C. Ord Regiments[nb 1] Commander: Brigadier General J. E. B. Stuart Regiments[3] At about noon, Ord arrived at the intersection of the Georgetown Pike and Leesburg Pike in the village of Dranesville, where he encountered Stuart's advance cavalry pickets, which were quickly driven off by the Union force.

While the Confederate infantry was deploying, the 1st Kentucky mistook the 6th South Carolina for Union troops and opened fire, which was quickly returned by the Carolinians.