After fighting with his regiment in the Battle of Peebles's Farm (September 30–October 2), Bonnaffon then performed the act of valor which resulted in his being awarded the U.S. Medal of Honor. While leading his men in the Battle of Boydton Plank Road, Virginia on October 27, 1864 as a member of Brigadier-General Regis de Trobriand's staff (2nd Corps, 1st Brigade, 3rd Division), he was severely wounded in action as he rallied his troops "in the face of a terrible fire of musketry", according to his Medal of Honor citation. Inspired by his leadership, his men went on to check what was shaping up to be a Confederate States Army rout of the Union Army that day.