Battle of Loudoun Heights The Battle of Loudoun Heights was a small cavalry skirmish during the American Civil War between John Mosby ' s Rangers and Major Henry A . Cole ' s 1st Potomac Home Brigade Maryland Cavalry on January 9 , 1864 , in Loudoun County , Virginia . Cole ' s Cavalry successfully defended a night raid against their camp on Loudoun Heights . The fight was one of the first engagements in which Union forces held their own against Mosby ' s vaunted partisans . Background . On January 1 , 1864 , eighty members of Cole ' s Maryland Cavalry , led by Captain A . N . Hunter , entered the region colloquially known as " Mosby ' s Confederacy " around Upperville and Rectortown , Virginia . With Mosby off on a scout in Fairfax , Capt . William " Billy " Smith rounded up 32 Rangers and set off in pursuit of the Federals . The Rangers caught up with Hunter ' s force near Middleburg . Captain Hunter quickly deployed his men into battle line just as Smith ordered a charge . The Federal line soon crumbled when Hunter ' s horse was killed , tumbling the captain to the ground . The Union cavalry hastily retreated towards Middleburg , but not before losing 57 killed , wounded or captured , as well as 60 horses seized by the Rangers . Within a week , Cole ' s camp atop Loudoun Heights had been discovered , thanks to the work of Benjamin Franklin Stringfellow , a staff officer under J . E . B . Stuart temporarily attached to Mosby ' s command . Angered by the audacity of Cole ' s Cavalry to raid so deep into Mosby ' s territory and encouraged by the enemy ' s woeful performance at Middleburg , Mosby decided to attack Cole ' s main force , hoping to catch them unaware in their camp . The battle . On January 9 , Mosby ordered a rendezvous at Upperville , to which 100 Rangers responded . The partisan company set out for Loudoun Heights through deep snow and bitter cold , reaching Woodgrove around 8 p . m . and stopping for 2 hours at the home of Ranger Henry Heaton . Just north of Hillsboro , they met up with Stringfellow and his scouting party , who informed Mosby of the exact location and strength of Cole ' s camp . Spotting Federal pickets posted along the Hillsboro - Harpers Ferry Road , the Confederates turned and headed east toward the wooded western slope of Short Hill Mountain , which they followed until they came to the bank of the Potomac River . From there , they turned westward and made their way along the riverbank to the base of Loudoun Heights . As the Rangers made their way up mountain , they were forced to dismount , given the steep grade . They stopped once they were within of the Union camp . Mosby sent a detachment of men under Stringfellow to capture Cole ' s headquarters in the rear of the camp , while he took the rest of the men further up the hillside , until they were directly west of the camp . At around 3 a . m . , as Mosby prepared to order the attack , gunfire erupted from the direction of Stringfellow ' s position , followed by the distant appearance of horsemen riding towards Mosby from the direction of the enemy camp . Thinking the unknown party was Federals who had discovered Stringfellow and his men , Mosby ordered a charge . His Rangers descended upon the camp and attacked the horsemen , who turned out to be Stringfellow ' s squadron . It was several minutes before the two parties recognized each other in the darkness , but not before several Confederates had been hit by friendly fire . In the meantime , Cole ' s men were awakened by the gunfire . Led by Captain George W . F . Vernon , of Company A , the men grabbed their weapons and hastily formed a dismounted battle line , though many were barely dressed . Despite the darkness , the Federals easily identified the Rangers , who stood out as they were the only ones on horses . Their initial volley dropped several Confederates , many of whom were caught out in the open along the road . In the confusion of the 45 minute fight that followed , several Rangers retreated and , soon afterward , with the sound of Federal infantry approaching from Harpers Ferry , Mosby ordered a general withdrawal . The Rangers escaped with 6 prisoners ( pickets from Co . B of Cole ' s Cavalry , all taken from their post along the Hillsboro road at the crossing of Piney Run ) and nearly 60 horses , but were forced to leave their dead and seriously wounded behind . A few miles beyond the Union camp , Mosby halted and sent two Rangers back under a flag of truce to exchange the prisoners for their dead and wounded , which included Billy Smith and First Lieutenant Thomas Turner . Major Cole , however , declined the offer , and the Rangers left and made their way back towards Mosby ' s Confederacy . Aftermath . Mosby ' s Rangers suffered 14 casualties — 4 dead , 4 mortally wounded , 5 wounded and 1 captured . Among the wounded was William " Willie " Mosby , John ' s brother . Of the dead , it was believed that 3 were victims of friendly fire . Cole suffered 6 dead , 14 wounded , and 6 captured . For their performance in the fight , the first in which Federals had bested Mosby ' s Rangers , Cole was promoted from major to colonel and Vernon from captain to lieutenant colonel .