If any doubts remained as to the Union cavalry's equality with its Southern counterparts, they were dispelled during Ulysses S. Grant's Overland Campaign. The Cavalry Corps, now consisting of four divisions, was placed under command of the fiery Phillip Sheridan. In the early stages of the campaign, they engaged Stuart's cavalry in a series of ferocious, bloody battles, killing General Stuart at Yellow Tavern. Stuart's successor, Wade Hampton, proved to be an equally formidable foe at the battles of Haw's Shop, Old Church, Trevilian Station, and Battle of Saint Mary's Church. The Union cavalry spent most of the Petersburg Campaign trying to cut rail lines from Petersburg and Richmond. The bulk of the cavalry was sent under Sheridan to join the Army of the Shenandoah during Sheridan's campaign against Jubal Early in the summer of 1864 (see Valley Campaigns of 1864).