On the evening of July 4, 1864, Union Colonel Charles Lowell sent Major William Forbes from Fairfax with 157 horse soldiers of the 2nd Massachusetts and 13th New York Cavalry detachments on patrol between Aldie and Leesburg to report any Confederate movements, while Lieutenant Colonel John S. Mosby and his cavalrymen were encamped at Point of Rocks. On the morning of July 5, Forbes passed through Aldie and found all quiet, then continued north past Ball's Mill to Leesburg before returning to camp south of the mill. On the evening of July 5, Mosby received a report that Union cavalry was in Leesburg, moved around Leesburg, and halted near Waterford. On the morning of July 6, Forbes broke camp and rode by Balls Mill to Leesburg, and finding no evidence of Mosby's Rangers, returned to Goose Creek. That same morning, Mosby rode to Leesburg but found that Forbes had departed toward Oatlands, and the Rangers headed south for a possible ambush. During the afternoon of July 6, Forbes moved east on Little River Turnpike and halted near the Skinner farmhouse as Mosby's scouts shadowed his cavalry and moved onto the turnpike east of the Federal troopers. Later that afternoon, Mosby moved west and confronted Forbes at Mount Zion Church and the Skinner farm, where the mounted Rangers, supported by a cannon, charged Forbes's dismounted cavalry, either capturing them or forcing them from the field.
