Hotchkiss thus describes the field of operations of this morning:  “The first line of works occupied by the Federal troops had been thrown up in the night, and was very formidable.  The engineer division of the Union Army consisted of near four thousand men, and these had been unremittingly engaged in its construction.  A vast number of trees had been felled, and formed into a heavy rampart, all approach to which was rendered extremely difficult by an abattis of limbs and brushwood.  On the south side of the road this line is situated upon a ridge, on the Chancellorsville side of Lewis Creek, one of the numerous head-waters of the Mattapony.  It is intersected by the smaller branches of this creek, and the ravines in which they run.  These ravines extended behind the Federal lines, almost to the plank road, and afforded excellent positions for successive stands.  In the morning, Sickles extended to the west of the creek, and held the elevated plateau at Hazel Grove.  This is the most commanding point, except Fairview, in the vicinity.  On the north of the plank road, the ground is more level.  The line thus crossed several small branches, the origin of some small tributaries of the Rappahannock, but the ravines on that side are not considerable.  From the ridge occupied by the first line, the ground falls away to the east, until the valley of another branch of Lewis Creek is reached.  The depression here is considerable, and gives an abrupt slope to the Fairview hill, which rises directly from it on the eastern side.  From the first line of the creek, extends on both sides of the road a dense forest.  From the latter point to Fairview heights, and to Chancellorsville, on the south side of the road, the country is cleared.  This clearing is bounded on the south by a drain, which runs from near Chancellorsville, between Fairview and the works occupied by Slocum.  It extends some distance on the north of the road.

“Behind the front line of works, there were some defences in the valley near the creek, not constituting a connecting line, however; and these in turn were succeeded by the second main line of works, which covered the Fairview heights, and were more strongly constructed even than the first.”

It was at just the time of Rodes’s assault, that Birney had received orders to withdraw from his cardinal position at the angle made by Geary and Williams, and to form as a second and third line near the plank road, a duty there was an abundance of troops to fill.  He retired, and ployed into brigade columns by regiments, immediately beyond the crest of Fairview hill.  Here, placing batteries in position, he shelled the field from which he had just withdrawn.  This crest, however, Archer speedily occupied; and on its summit Stuart, with better foresight than Hooker, posted some thirty guns under Walker, which enfiladed our lines with murderous effect during the remainder of the combat of Sunday, and contributed largely to our defeat.