On the night of October 20, 1861, a small Federal scouting party crossed the Potomac River from Maryland to learn whether recent troop movements signaled a Confederate withdrawal from Leesburg. Moving inland from Ball’s Bluff, the Federals passed this point, crested a low ridge near the Jackson house, and in the dim moonlight mistook a row of trees for a Confederate camp. After hearing this report, Brig. Gen. Charles P. Stone quickly organized a raiding party, and five companies of the 15th Massachusetts led by Col. Charles Devens spent several hours quietly crossing the river from Harrison’s Island. At dawn they marched up the path intending to destroy the supposed camp and return to Maryland, but the camp did not exist, and by the time the mistake was reported to Stone, an unintended battle had begun. At 7:30 a.m. on October 21, Company K of the 17th Mississippi clashed with the Massachusetts men near the Jackson house. Stone remained in Maryland at Edward’s Ferry and, after learning of the patrol’s error but not yet knowing that fighting had occurred, ordered Col. Edward D. Baker to assess the situation. While traveling upriver, Baker learned from a messenger that fighting had started, and the messenger then continued downriver to alert Stone. Col. Nathan G. “Shanks” Evans directed Confederate forces from an earthen fort on nearby Edwards Ferry Road, and by midmorning he had committed four more companies of Mississippi infantry and three companies of Virginia cavalry to the fight. Devens’ men withdrew to a wood line near the Jackson house. About 12:30, the 8th Virginia Infantry arrived, and shortly afterward the Confederate line, now nearly 700 strong, attacked Devens’ roughly 650 Federal troops. The skirmish lasted perhaps an hour, after which Devens withdrew to the bluff as the most serious fighting was about to begin.