Modern topographic map showing the approximate positions of the opposing armies before the final stage of the Battle of Opequon, September 19, 1864. The black square shows the approximate location of Ft. Collier. Infantry are represented by the thicker, solid lines; cavalry by the thinner, broken lines. The 116th Ohio, indicated by the red circle, was on the extreme left of Thoburn's 1st Division of Crook's 8th Corps. Crook's flanking maneuver collapsed the Confederate left, and renewed pressure from the 6th and 19th Corps against their right drove the Rebels back toward Winchester. A thundering charge by the Union cavalry units into their rear completed the rout and the surviving Confederates retreated south to Fishers Hill.