Adam Badeau, Military history of Ulysses S. Grant from April 1861 to April 1865. Volume 1

[346] approach was a full sap, covered on both sides by gabions, and, on the top, by a roof of cane gabions. This protection was necessary till it reached the foot of the hills, on the crest of which the enemy's line was situated; the hills, however, were so steep as to afford perfect shelter from the hostile fire, up to within thirty yards of the parapet. At this part of the line, the timber had been cleared some time before, but the ground, in front of the rebel trench, was obstructed by an entanglement of posts and vines.

The principal position, however, for Sherman's batteries was on the ridge, about four hundred yards from the enemy's line, and at a point near the head of the stream, on the north side of the rebel defences. Four batteries, of six guns each, were disposed on Blair's front. His approach started from the left of the principal battery, near the Graveyard road, and was directed against the salient of the work commanding this road, the same which he had assaulted on the 22d of May. It was carried steadily forward, till it reached a large oak-tree, standing alone, about one hundred and twenty yards from the rebel works. This tree was subsequently known as the ‘Lone Tree,’ and gave name to a battery erected here, or rather to a parapet and place of arms. The place of arms was furnished with communications with both flanks, by boyaux leading down into the ravines, and was well revetted, and prepared with a banquette for sharpshooters. From its right, a new double sap was started, following around the hillside; this was, at first, directed just outside the enemy's line, but then, turning, it ran up-hill in the direction of the rebel salient. At the turn, it was defiled, by excavating it till the part of the hillside towards the enemy became a complete