by sharpshooters led by Captain James T. Stuart from the 49th Pennsylvania Infantry Regiment, who were armed with Spencer repeating rifles. Without having to engage in hand-to-hand combat, Hamblin's brigade overcame the defenders, many of whom already were retreating from flank fire from adjacent Union soldiers. Wright left Hamblin's brigade to guard the captured line at its north end as he reorganized most of the remaining men of the corps to move south. On the left of the Sixth Corps' formation, Major General Truman Seymour's division, led by Lieutenant Colonel J. Warren Keifer's brigade, dispersed MacRae's North Carolina brigade. Keifer's regiments quickly drove off the 28th North Carolina Infantry Regiment, captured 10 pieces of artillery, a large number of prisoners, three battle flags and Major General Henry Heth's headquarters flag. Colonel William S. Truex led the rest of Seymour's division against two North Carolina regiments and a six-gun artillery battery on the far left of the VI Corps assault. The Confederates held their fire when their own pickets began to flee toward the main line in front of the advancing Union soldiers, who overwhelmed the main Confederate line. After about 30 minutes of heavy fighting, the Confederate lines had been broken and Humphrey's VI Corps had made a decisive breakthrough. As the VI Corps surged forward, some soldiers ultimately crossed the Boydton Plank Road and reached the South Side Railroad about away. Union Army Chief Engineer John G. Barnard estimated Union casualties in the VI Corps breakthrough at about 1,100 killed and wounded, "all of which occurred in the space of about fifteen minutes." Confederate casualties are unknown but the majority of them were taken prisoner rather than killed or wounded. General Grant estimated the VI Corps took about 3,000 prisoners, which historian A. Wilson Greene states is "probably not far wrong." A.P. Hill killed A.P. Hill and Robert E. Lee both learned of the breakthrough soon after it occurred. At about 5:30 a.m. Hill rode to meet with Lee, then set out to organize the defense along the Boydton Plank Road Line. After the initial breakthrough, stragglers from Wright's corps continued straight forward while most of the VI Corps troops turned to the left. West of the Boydton Plank Road, two stragglers from the 138th Pennsylvania Infantry Regiment, Corporal John W. Mauk and Private Daniel Wolford, stumbled upon Confederate Lieutenant General A. P. Hill and an aide, Sergeant George