As Barksdale's brigade withdrew, he was relieved at the sunken road by the Eighteenth and Twenty-fourth Georgia Regiments and Cobb's Georgia Legion, General T. R. R. Cobb in command.
The Third Grand Division had no severe work in laying the bridges below Deep Run, and were ready for co-operation some hours in advance of the right.
The Federals occupied the 12th in moving the Right Grand Division into the city by the upper bridges, and the Left Grand Division by the bridges below Deep Creek. One hundred and four guns crossed with the right, one hundred and twenty with the left. The Centre Grand Division was held in reserve. Two divisions of the Third Corps were sent to the lower bridges during the night to support the battle of the left, and were ordered over on the 13th.
The plan of battle by the Federal commander, in brief, was to drive the Confederate right back into the highlands and follow that success by attacking the Confederate left by his Right Grand Division.
The _beginning_ only of this plan was carried out. The Left Grand Division having duly crossed the river at the lower bridges on the 12th,--the Sixth Corps and Bayard's brigade of cavalry, then the First Corps,--the Sixth deployed two divisions, supported by the third, parallel to the old Richmond road; the First formed at right angles to the Sixth, its right on the left of the Sixth, its left on the river, two divisions on the front line, one in support. The cavalry was sent out to reconnoitre. The entire field of the command was an open plain between the highlands and the river, traversed by the old Richmond road, which had well-formed embankments and ditches on both sides.
The Federal troops of their left divisions were in full view of the heights (Lee's Hill) occupied by the Confederates; those of the right were concealed by the buildings of Fredericksburg and under the river banks, and their bridges were under the steep also. The two brigades on the right of the Sixth Corps were to the right of Deep Run; the others, of the First and Sixth Corps, on the left. The batteries of the corps were under authority of corps commanders. There were but few shots exchanged during the 12th, and these not of great damage.