and that he planned an attack along the Petersburg lines at 4:00 a.m. Grant said he could give Sheridan no specific instructions but "would like you however to get something done to the South Side Road even if they do not tear up a mile of it." Sheridan replied at 12:30 a.m. that he planned to sweep the White Oak Road and all north of it down to Petersburg. He sent no troops to the South Side Railroad but moved against the White Oak Road Line flank. Artillery barrage As ordered by General Grant, at 10:00 p.m., Union artillery opened fire with 150 guns on the Confederate lines opposite the Union Army's Petersburg lines until 2:00 a.m. The Confederates did not leave the lines that night and the Union assault began at about 4:30 a.m. Plan of attack Major Generals Andrew Humphreys with the II Corps, Horatio Wright with the VI Corps, John Parke with the IX Corps and Edward Ord, commander of the Army of the James, with Major General John Gibbon's XXIV Corps had been planning the attack scheduled for 4:00 a.m. on April 2, 1865 for three days. Grant directed them to carry the trenches and fortifications opposite their corps and move toward Petersburg. General Sheridan was instructed to start at dawn and move up the White Oak Road and all north of it to Petersburg as he had informed Grant that he would. Opposite Ord and Wright were the Confederate brigades of Brigadier Generals Joseph R. Davis, under the command of Colonel Andrew M. Nelson, William McComb, James H. Lane and Edward L. Thomas of Major General Cadmus M. Wilcox's division of A.P. Hill's corps. Opposite Parke was Major General John B. Gordon's corps of about 7,600 men. Battle Sixth Corps breakthrough at Boydton Plank Road Line After careful planning during the two preceding days, Wright had chosen to attack the Confederate line from the Jones house to the left end of his line opposite Union Forts Fisher and Welch. The land between the lines of the two armies was clear of trees and had few natural obstacles except for some marshes near the left end of Wright's line. To the right of the point of attack were inundated areas and strong defenses near the Lead Works. The Confederates had batteries sited every few hundred yards along their line. The capture of the Confederate picket line