Despite the fame of Stonewall Jackson's victory on May 2, it did not result in a significant military advantage for the Army of Northern Virginia. Howard's XI Corps had been defeated, but the Army of the Potomac remained a potent force and Reynolds's I Corps had arrived overnight, which replaced Howard's losses. About 76,000 Union men faced 43,000 Confederate at the Chancellorsville front. The two halves of Lee's army at Chancellorsville were separated by Sickles's III Corps, which occupied a strong position on high ground at Hazel Grove.^[14]

Unless Lee could devise a plan to eject Sickles from Hazel Grove and combine the two halves of his army, he would have little chance of success in assaulting the formidable Union earthworks around Chancellorsville. Fortunately for Lee, Joseph Hooker inadvertently cooperated. Early on May 3, Hooker ordered Sickles to move from Hazel Grove to a new position on the Plank Road. As they were withdrawing, the trailing elements of Sickles's corps were attacked by the Confederate brigade of Brig. Gen. James J. Archer, which captured about 100 prisoners and four cannons. Hazel Grove was soon turned into a powerful artillery platform with 30 guns under Col. Porter Alexander.^[14]

After Jackson was wounded on May 2, command of the Second Corps fell to his senior division commander, Maj. Gen. A.P. Hill. Hill was soon wounded himself. He consulted with Brig. Gen. Robert E. Rodes, the next most senior general in the corps, and Rodes acquiesced in Hill's decision to summon Maj. Gen. J.E.B. Stuart to take command, notifying Lee after the fact. Brig. Gen. Henry Heth replaced Hill in division command.^[15]

Although Stuart was a cavalryman who had never commanded infantry before, he was to deliver a creditable performance at Chancellorsville. By the morning of May 3, the Union line resembled a horseshoe. The center was held by the III, XII, and II Corps. On the left were the remnants of the XI Corps, and the right was held by the V and I Corps. On the western side of the Chancellorsville salient, Stuart organized his three divisions to straddle the Plank Road: Heth's in the advance, Colston's 300–500 yards behind, and Rodes's, whose men had done the hardest fighting on May 2, near the Wilderness Church.^[15]