On the 2d Johnston knew that McPherson's army was marching to interpose between him and the Chattahoochee, and issued his orders for the evacuation of the Marietta lines in the night, and the occupation of the position beyond the Nickajack. [Footnote: Official Records, vol. xxxviii. pt. v. p. 860.] But Thomas and McPherson both followed so vigorously that the Confederate general saw that he could not cover the crossings of the river which Stoneman's cavalry was already reaching on our right, and in the night of the 4th he again retired, this time to intrenchments with both flanks resting on the river and covering the railway bridge with two or three of the principal ferries. With his usual prudence, Johnston had prepared both these lines with the aid of the Georgia militia under General Gustavus W. Smith, who, being himself an engineer, was admirably fitted to co-operate with the plans of the staff. Again a few days had to be given to repairs of the railroad and a readjustment of the depots and means of supply, whilst careful reconnoissances of the river were made both above and below the Confederate position. Schofield's corps was placed in reserve near the railway, at Smyrna Camp ground, and on the 8th my division was assigned the duty of making a crossing of the Chattahoochee, and laying pontoon bridges at Isham's ford and ferry at the mouth of Soap Creek, [Footnote: In the official Atlas, pl. lx., two creeks are named Rottenwood. The upper one of these with paper-mills upon it is Soap Creek. The ford was sometimes called Cavalry Ford in the Confederate dispatches. For particulars of the movements at this period of the campaign, see "Atlanta," chap. xi.] about nine miles above the railway crossing of the river. Johnston does not seem to have been well served by his cavalry on this occasion, for the crossing was gained and two bridges laid with only trifling opposition, and my division was over and strongly intrenched before any concentration of the enemy was made in my front. [Footnote: Official Records, vol. xxxviii. pt. v. pp. 85, 89, 93.] This, of course, decided Johnston to abandon the northern bank of the river, and he selected a strong position behind Peach-tree Creek as the next line of defence for Atlanta, burning the railway bridge and other bridges behind him. Several days were occupied by Sherman in moving McPherson's command to Roswell, twenty miles above the railway, and building a trestle-bridge there, in accumulating supplies and organizing transportation for another considerable absence from the railroad. By the 17th the army was over the Chattahoochee, McPherson on the left, Schoneld next, and Thomas from the centre to the right. A general wheel of the whole toward the right was ordered, to find and drive back the enemy upon Atlanta.