Two related battles Hostile_encounter were fought Hostile_encounter nearby on May 3 in the vicinity of Fredericksburg .

Combined with the Union force facing Fredericksburg , Hooker planned Arranging a double envelopment , attacking Attack Lee from both his front and rear .

On May 1 , Hooker advanced Self_motion from Chancellorsville toward Lee , but the Confederate general split Destroying his army in the face of superior numbers , leaving Departing a small force at Fredericksburg to deter Hindering Maj. Gen. John Sedgwick from advancing , while he attacked Attack Hooker 's advance with about four-fifths of his army .

That same day , Sedgwick advanced Self_motion across the Rappahannock River , defeated Getting the small Confederate force at Marye 's Heights in the Second Battle of Fredericksburg , and then moved Self_motion to the west .

The Confederates used Using the Potomac ’ s banks as gun positions Placing to halt Union traffic on the river , protecting Defending Manassas Junction to the west and Fredericksburg to the south and to close Process_end the Potomac River to shipping Sending and isolate Hindering Washington .