<P> Grant's own popularity had risen, and there was talk that a Union victory early in the year could lead to his candidacy for the presidency . He was aware of the rumors, but had ruled out a political candidacy; the possibility would soon vanish with delays on the battlefield . </P> <P> The Overland Campaign was a series of brutal battles fought in Virginia for seven weeks during May and June 1864 . Sigel's and Butler's efforts sputtered, and Grant was left alone to fight Lee . On the morning of Wednesday, May 4, dressed in his full uniform, with sword at his side, Grant rode out from his headquarters at Culpeper towards Germanna Ford, mounted on his war horse, Cincinnati . That day Grant crossed the Rapidian unopposed, while supplies were transported on four pontoon bridges . On May 5, the Union army attacked Lee in the Wilderness, a three - day battle with estimated casualties of 17,666 Union and 11,125 Confederate . Rather than retreat, Grant flanked Lee's army to the southeast and attempted to wedge his forces between Lee and Richmond at Spotsylvania Court House . Lee's army got to Spotsylvania first and a costly battle ensued, lasting thirteen days, with high casualties . On May 12, Grant attempted to break through Lee's Muleshoe salient guarded by Confederate artillery, resulting in one of the bloodiest assaults of the Civil War, known as the Bloody Angle . Unable to break Lee's lines, Grant again flanked the rebels to the southeast, meeting at North Anna, where a battle lasted three days . </P> <P> Grant maneuvered his army to Cold Harbor, a vital railroad hub that linked to Richmond, but Lee's men had the defensive advantage and were already entrenched . On the third day of the thirteen - day battle, Grant led a costly assault and was soon castigated as "the Butcher" by the Northern press after taking 52,788 Union casualties; Lee's Confederate army suffered 32,907 casualties, but he was less able to replace them . This battle was the second of two that Grant later said he regretted (the other being his initial assault on Vicksburg). Undetected by Lee, Grant moved his army south of the James River, freed Butler from the Bermuda Hundred, and advanced toward Petersburg, Virginia's central railroad hub . After crossing the James, Grant arrived at Petersburg, threatening nearby Richmond . Beauregard defended the city, and Lee's veteran reinforcements soon arrived, resulting in a nine - month siege . Northern resentment grew as the war dragged on . Lee was forced to defend Richmond, unable to reinforce other Confederate forces . Sheridan was assigned command of the Union Army of the Shenandoah and Grant directed him to "follow the enemy to their death" and to destroy vital Confederate supplies in the Shenandoah Valley . When Sheridan reported suffering attacks by John S. Mosby's irregular Confederate cavalry, Grant recommended rounding up their families for imprisonment as hostages at Fort McHenry . After Grant's abortive attempt to capture Petersburg, Lincoln supported Grant in his decision to continue . Because of the high casualties, Lincoln arrived at Grant's headquarters at City Point on June 21 to assess the state of Grant's army, meeting with Grant and Admiral Porter . By the time Lincoln departed his appreciation for Grant had grown . </P> <P> At Petersburg, Grant approved a plan to blow up part of the enemy trenches from an underground tunnel . The explosion created a crater, into which poorly led Union troops poured . Recovering from the surprise, Confederates surrounded the crater and easily picked off Union troops within it . The Union's 3,500 casualties outnumbered the Confederates' by three - to - one; although the plan could have been successful if implemented correctly, Grant admitted the tactic had been a "stupendous failure". Rather than fight Lee in a full frontal attack as he had done at Cold Harbor, Grant continued to extend Lee's defenses south and west of Petersburg to capture essential railroad links . </P>

Who was appointed commander of all union armies in march 1964