At the Battle of Chaffin's Farm, on September 29, 1864, Harris' regiment was among a division of black troops assigned to attack the center of the Confederate defenses at New Market Heights. The defenses consisted of two lines of abatis and one line of palisades manned by Brigadier General John Gregg's Texas Brigade. The attack was met with intense Confederate fire; over fifty percent of the black troops were killed, captured, or wounded. The initial attack stalled at the abatis, but when a renewed effort began, Harris and two other men of the 38th USCT, Private William H. Barnes and Sergeant Edward Ratcliff, ran at the head of the assault. Being the first to breach the defenses, the three soldiers engaged the Confederates in hand-to-hand combat. They were soon joined by the remainder of their division, and the Confederate force was routed.