Hood, during the night of July 21st, had withdrawn from his Peach-Tree line, had occupied the fortified line of Atlanta, facing north and east, with Stewart’s—­formerly Polk’s—­corps and part of Hardee’s, and with G. W. Smith’s division of militia.  His own corps, and part of Hardee’s, had marched out to the road leading from McDonough to Decatur, and had turned so as to strike the left and, rear of McPherson’s line “in air.”  At the same time he had sent Wheeler’s division of cavalry against the trains parked in Decatur.  Unluckily for us, I had sent away the whole of Garrard’s division of cavalry during the night of the 20th, with orders to proceed to Covington, thirty miles east, to burn two important bridges across the Ulcofauhatchee and Yellow Rivers, to tear up the railroad, to damage it as much as possible from Stone Mountain eastward, and to be gone four days; so that McPherson had no cavalry in hand to guard that flank.

The enemy was therefore enabled, under cover or the forest, to approach quite near before he was discovered; indeed, his skirmish-line had worked through the timber and got into the field to the rear of Giles A. Smith’s division of the Seventeenth Corps unseen, had captured Murray’s battery of regular artillery, moving through these woods entirely unguarded, and had got possession of several of the hospital camps.  The right of this rebel line struck Dodge’s troops in motion; but, fortunately, this corps (Sixteenth) had only to halt, face to the left, and was in line of battle; and this corps not only held in check the enemy, but drove him back through the woods.  About the same time this same force had struck General Giles A. Smith’s left flank, doubled it back, captured four guns in position and the party engaged in building the very battery which was the special object of McPherson’s visit to me, and almost enveloped the entire left flank.  The men, however, were skillful and brave, and fought for a time with their backs to Atlanta.  They gradually fell back, compressing their own line, and gaining strength by making junction with Leggett’s division of the Seventeenth Corps, well and strongly posted on the hill.  One or two brigades of the Fifteenth Corps, ordered by McPherson, came rapidly across the open field to the rear, from the direction of the railroad, filled up the gap from Blair’s new left to the head of Dodge’s column—­now facing to the general left—­thus forming a strong left flank, at right angles to the original line of battle.  The enemy attacked, boldly and repeatedly, the whole of this flank, but met an equally fierce resistance; and on that ground a bloody battle raged from little after noon till into the night.  A part of Hood’s plan of action was to sally from Atlanta at the same moment; but this sally was not, for some reason, simultaneous, for the first attack on our extreme left flank had been checked and repulsed before the sally came from the direction of Atlanta.  Meantime, Colonel Sprague, in Decatur,