On June 21, the Union II Corps, supported by the VI Corps, attempted to cut the Weldon Railroad, one of the major supply lines into Petersburg. The movement was preceded by Wilson’s cavalry division which began destroying tracks. On June 22, troops from Lt. Gen. A.P. Hill’s corps led by Brig. Gen. William Mahone counterattacked, forcing the II Corps away from the railroad to positions on the Jerusalem Plank Road. Although the Federals were driven from their advanced positions, they were able to extend their siege lines farther to the west.