How did the battle of the wilderness effect the civl war?

because

NEW RESPONDENT

For the first time from the outbreak of Civil War, the Army of Potomac, after having sustained a setback or, better said in this case, a stalemate, didn't retreat but advanced towards Richmond, forcing Lee's Army to follow in order to prevent of being separated from its Capital City.

By so doing, Grant started a new phase of his strategy based upon the "Strategic Intimidation", by which eventually managed to deprive Lee of his "freedom of movements" and indissolubly pinned him down to the Richmond defense.

Also Lee was a master in developing the same strategy and he made a good use of that sending the II Corp of his Army, under Gen. Early, to the Shenandoah Valley with the goals of get rid of the Union Forces there and then menace Washington. By that mean he gave several troubles to Grant during his Overland Campaign, succeeding (partly) in delaying the final act of the campaign until Sheridan destroyed the Confederate forces in the Valley, joining then the Army of Potomac.

Of course, the final outcome was mainly possible thanks to the Union Army's great superiority in number and means