After an exhausting night of dragging 20 cannon along the river and up the ravines to this site on Chambers (Murphy) Farm, General A.P. Hill and his 3,500 men sprang their trap on the unsuspecting Union army. Before dawn on the last day of the battle, the Confederates aimed their cannon at the Union line, only 1,000 yards away. When the morning fog lifted Hill signaled his artillerymen to open fire. Startled but alert, the Federals vigorously returned the fire. But an hour later their cannon were silent, triggering a Confederate charge. Hill wrote, "General Pender commenced his advance, when, the enemy again opening?[we ran] forward to within 400 yards, and, quickly?poured in a damaging fire. The enemy now displayed the white flag." The Union garrison at Harpers Ferry fell.