The Battle of Unison or Battle of Union refers to a series of American Civil War cavalry skirmishes in Loudoun County, Virginia, between October 31 – November 2, 1862, between the Confederate forces of J.E.B. Stuart and various units of the Union Army of the Potomac. Although driven from the field in individual engagements, Stuart accomplished his mission to delay the enemy and screen the movements of the retreating Army of Northern Virginia.