August 13, it was decided to move all the army, except one corps (which was to be thrown back to the Chattahoochee railroad bridge), around Atlanta upon the railroad running south from East Point, and the pontoon train of the Army of the Cumberland was moved from the railroad bridge, along the north side of the river, to the Sandtown Ferry preparatory to throwing a bridge across the river at that point.
August 14, nothing was done by the engineer department, waiting further instructions.
August 15, the line of Proctor's Creek was examined for the purpose of selecting a defensive flank to be used when the Army of the Cumberland was withdrawn. Two pontoon bridges were laid at sandtown Ferry.
August 16, accompanied by Lieutenants Twining and Damrell, I visited our extreme right and rode over the lines of the Army of the Ohio, as well as the position which Lieutenant Twining had already selected south of Utoy Creek to be occupied by the Army of the Ohio upon the withdrawal of the Armies of the Tennessee and the Cumberland. The position was admirably chosen. A trestle bridge was commenced at Sandtown Ferry to replace the pontoon bridges at that point.
August 17, orders for the movement of the army to the rear of East Point were promulgated. The cavalry command of General Kilpatrick started upon a raid to the southward of Atlanta.
August 18 and 19, the troops kept hard at work to induce the enemy to believe that we contemplated no movement upon his rear of greater importance than a cavalry raid. The entire force of engineer offices hard at work reconnoitering all the roads to our right as far as enemy's cavalry would permit.
August 20, a force of infantry reached the Atlanta and West Point Railroad near Red Oak Station, and tore up a portion of the track. Our batteries were completed along our whole line and we were ready for any emergency.
August 21 and 22, the pioneer force was all kept at work preparing siege materials. The batteries along our whole line kept up a slow but steady fire both upon the enemy's lines and upon the city of Atlanta. The remarks in this paragraph apply to every day for the last two weeks.
August 23, under instructions from the major-general commanding, I went to the Chattahoochee railroad bridge and selected a line to be occupied by the corps (Twentieth), which was to be left behind during our movement to the rear of Atlanta, and gave Lieutenant Ludlow full instructions concerning the building of it. The position held by the Fifteenth Army Corps during the battle of the 28th of July was selected by Captain Reese as a flank to be occupied by the Army of the Tennessee upon the withdrawal of the Army of the Cumberland. General Kilpatrick's cavalry command returned, having passed entirely around Atlanta.
August 24, at work upon the new flank referred to above. Reconnaissance pushed to the right almost as far as Campbellton.
August 25, at might the grand movement commenced by the withdrawal of the Fourth and twentieth Corps. The latter marched directly to the railroad bridge, Pace's and Turner's Ferries, while the former passing in rear of the Army of the Tennessee, bivouacked next night on Utoy Creek. Before the movement began its left had rested on the Decatur road.