Thomas planned a huge wheeling movement that would ultimately come down on the Confederates' exposed left flank. Wilson's Cavalry Corps moved west on Charlotte Pike once an early morning fog dissipated, driving off the Confederate cavalry patrolling the area between the Confederate left and the Cumberland River. Smith's XVI Corps detachment followed, turning south after a mile or so towards the Confederate flank. The cavalrymen formed on Smith's right flank. Schofield's XXIII followed in reserve, and as the assault moved south a gap opened between Smith and Wilson which Schofield was directed to fill. At about 2:30 pm, the Union troops attacked the five redoubts guarding the Confederate left. Four brigades, two of cavalry and two of infantry, overran Redoubt No. 4 and then Redoubt No. 5, notwithstanding the spirited resistance of the defenders of Redoubt No. 4. Another of Smith's brigades captured Redoubt No. 3; however, its commander, Col. Sylvester G. Hill, was killed by Confederate artillery firing from Redoubt No. 2. He was the highest-ranking Union officer killed in the battle. Smith's troops proceeded to Redoubt No. 2, which was quickly captured.