W. Field's division of Longstreet's corps, two brigades from Gordon's corps and some of General Wilcox's men to occupy the Dimmock Line defenses. VI Corps drives back artillery When the VI Corps advanced to Gibbon's left at the start of the attack on Fort Gregg, only Confederate artillery fire from Lieutenant Colonel William T. Poague's Battery, directed by Confederate staff officer Giles Buckner Cooke, opposed them. The battery was operating from a position next to Lee's command post at the Turnbull House, also known as Edge Hill, located west of Rohoic Creek in front of the Dimmock Line. Getty's division had moved near the Turnbull House with limited protection from Poague's artillery. Getty determined to attack the 13 guns that were turned against his division from that location. Getty's first attack was turned back but Colonel Hyde's men successfully outflanked the batteries, leading to the withdrawal of the gunners and the 9 guns that had not been immobilized. Field's division occupied the Dimmock Line as the Confederate artillerists fled the Turnbull House, while General Lee also rode from the Turnbull House to the protection of the Dimmock Line as VI Corps infantrymen approached close enough to see him leave. After dealing with more artillery fire from across the Appomattox River, General Grant ordered the exhausted VI Corps troops to halt and rest, which they did after completing some fortifications near the Turnbull House. Parke's attack on Fort Mahone The Union Army's IX Corps under Major General John G. Parke occupied the original trenches east of Petersburg that were captured in June 1864. Facing Parke was a strong Confederate position along the Jerusalem Plank Road dominated by Fort Mahone (strengthened from the former Battery 29 and named after Major General William Mahone; also known as "Fort Damnation"), covered by batteries in six redoubts and manned by the forces of Major General John B. Gordon. The Confederates had built a strong secondary line about behind their main line. Union Fort Sedgwick was about from Fort Mahone. On the night of April 1, 1865, at 11:00 p.m., Parke sent men from Brigadier General Simon G. Griffin's brigade of Brigadier General (Brevet Major General) Robert B. Potter's division forward from a point near Fort Sedgwick (also known as "Fort Hell") to take Grimes's picket line. They captured 249 officers and men, about half of Colonel Edwin L. Hobson's brigade in the process. Parke was