Nashville and Chattanooga, being large depots of supply, were fortified and furnished with garrisons. A few other points had also to be garrisoned in some force, besides the numerous small posts and blockhouses. But after all deductions, Sherman still expected to take the field with an army of a hundred thousand men of all arms, and this was what he did. His returns for the 30th of April show his strength to have been 93,131 infantry, 12,455 cavalry, and 4537 artillery. [Footnote: Official Records, vol. xxxviii. pt. i. p. 115.] His cavalry were not all at the front, and fell short of the nominal strength. [Footnote: Memoirs, vol. ii. pp. 23, 24; Official Records, vol. xxxviii. pt. iv. p. 26.]
General Johnston's similar returns for the end of April show his army actually present at Dalton to have consisted of 54,500 infantry, cavalry, and artillery, not including part of a brigade at Resaca and some detachments en route. [Footnote:Id., vol. xxxii. pt. iii. p. 866.] General Polk was on his way to join with 14,000 men, [Footnote: Id., vol. xxxviii. pt. iv. pp. 670, 737, 740.] and these with about 5000 increase of Hardee's and Hood's corps reached Johnston before he was seriously engaged with Sherman, giving him an army of 75,000 men. [Footnote: For a careful analysis of these forces, see "Century War Book," vol. iv. p. 281, a statistical paper by Major E. C. Dawes; also "Atlanta," Appendix A. For the meaning of "effective total" in Confederate returns, see ante, p. 482.] The Richmond government only delayed ordering Polk to join Johnston until it was certain that Sherman intended to operate with a single army upon the Atlanta line, and Polk went even beyond what they seemed to expect of him in carrying the troops of his department to the army at Dalton.
Although he was not aware of the urgency of the Confederate government with Johnston to induce him to take the initiative and operate by turning our left flank, Sherman had considered the possibility of this. The Fourth Corps had been concentrated at Cleveland on the East Tennessee and Georgia Railway about a dozen miles north of the Georgia state line and thirty-five miles from Dalton. The line of this railway was the easy road out of northern Georgia into Tennessee, and pretty closely followed the old Federal road. Had Johnston marched northward, he must have taken this route, and would have found his way barred by the Fourth Corps, which was strong enough to retard his advance till Sherman could have concentrated to meet him. The railways made a nearly equilateral triangle of the country between Cleveland, Chattanooga, and Dalton. It was thirty-eight miles from Chattanooga to Dalton, and twenty-seven to Cleveland. The east side of the triangle was near the Cooyehuttee Creek, a stream heading quite close to Cleveland and uniting, below Dalton, with the Connasauga. This valley is narrow west of the river, and is, much of the way, separated by a high and sharp ridge from the very broken country, which makes up the greater part of the triangle, where the branches of the Chickamauga run northward in parallel valleys till they unite near Chattanooga, and empty into the Tennessee. For nearly forty miles, therefore, the waters on the east side of the dividing ridge run southward to the Gulf of Mexico, whilst on the west side they run northward to the Ohio.
Going south from Chattanooga, the railroad and the wagon roads have to thread their way from one valley to another, the latter climbing painfully the high ridges intervening, the former taking shorter cuts by deep excavations and tunnels. Within sight of Chattanooga the north end of Missionary Ridge is pierced for the railway where Grant's left wing fought in the battle which closed General Bragg's career as a commander in the field. Some twenty miles further on, another ridge is tunnelled where the railroad passes from the Chickamauga valley into that of Mill Creek, a small tributary of the Cooyehuttee, flowing eastward into that river in front of Dalton. Here, at Tunnel Hill, had been Johnston's advanced post during the winter, and Thomas's had been above Ringgold on the top of Taylor's ridge facing it on the west. But as Tunnel Hill did not extend many miles northward, and could be turned in that direction, the Confederates had made Dalton their intrenched camp, and were prepared to retire from Tunnel Hill whenever Sherman should advance in force.
The position at Dalton was an impregnable one to an attack in front on the Chattanooga road. Mill Creek breaks through the Chattanooga Mountains (here known by the local name of Rocky Face), by a crooked gorge flanked by precipitous cliffs called the Buzzards Roost. The west side of Rocky Face is a nearly perpendicular wall, and in the Mill Creek gorge, spurs from the sides so project as to enfilade the entrance like bastions. A little north of the gorge a larger spur from the ridge runs down to the east, connecting with a subordinate parallel ridge, and from the lower slope a line of heavy earthworks continued the defences toward the Cooyehuttee. Mill Creek had been dammed so as to make an inundation in the gorge, and the Confederates held the ridge and cliffs on both sides as well as the fortified line in the lower ground. Some three miles north of Mill Creek Gap, Rocky Face and Tunnel Hill break down into smaller disconnected hills, and here about Catoosa Springs a bit of more open country made a practicable connection between the centre of the Union Army at Ringgold and its left wing advancing from Cleveland. Johnston hoped that Sherman would dash himself against the walls of Rocky Face and suffer severe loss in doing so; and if the ridge was turned on the north by part of the Union Army, this wing would find itself in presence of the strong earthworks skirting Mill Creek, and would be so separated from the centre that he could reasonably hope to crush it. Sherman, of course, could know little of the Confederate position till he was near enough to reconnoitre it, and must find out by experiment how the nut was to be cracked.
On Thursday, the 5th of May, the Army of the Ohio under General Schofield was at Red Clay, a hamlet just south of the Georgia state line. My own division (the third) was encamped a mile in advance, at some springs which furnished a good supply of water. General Judah's division (the second) was at Red Clay. General Hovey's division (the first) was still at Blue Springs, Tennessee, covering the army trains and the repairs of the railway. The cavalry covered the left flank and reconnoitred forward toward Varnell's Station, skirmishing with the enemy's horse. The valley was a narrow one, tributary to the principal valley of the Connasauga, and, near my camp, was filled with a dense thicket of loblolly pine, a second growth which came up in the exhausted light soil of abandoned fields, and which we were to become very familiar with as we advanced into Georgia. As we could not see out in any direction except that of the road, I covered my front with a slashing of the trees by way of a rough abatis to prevent a surprise. We were now the left flank of the grand army.
When we passed Cleveland, the Fourth Corps took up its line of march, bearing away to the westward of ours and went into position at Catoosa Springs, about eight miles southwest of Red Clay, with a ridge intervening. Here General Howard became the left of the Army of the Cumberland, having Palmer's Corps (the Fourteenth), next beyond him facing Tunnel Hill, and Hooker's (the Twentieth) still farther to the southwest, marching by way of Woods Station over Taylor's Ridge upon Trickum in the upper valley of the East Chickamauga. Thomas's army was the heavy centre of the grand army, and his infantry was about two-thirds of the whole. This great preponderance of one organization was faulty in a purely military point of view, but Grant and Sherman both felt that it would not be wise to disturb the esprit de corps of the Cumberland Army by subdividing it, or to offend Thomas by diminishing it, and, anyhow, no such change could have been made without the concurrence of the President.
General McPherson's Army of the Tennessee was to constitute Sherman's right, but was a little delayed in its concentration. At this time it contained only Logan's Corps (the Fifteenth) and the left wing of the Sixteenth (Brigadier-General G. M. Dodge in command). It was moving behind the Army of the Cumberland, to Lee and Gordon's Mills, and thence upon Villanow. [Footnote: Official Records, vol. xxxviii. pt. iv. p. 39.] General Kenner Garrard's strong division of cavalry accompanied McPherson's movement.
Sherman was anxious to allow the enemy as little time for preparation as might be, yet, as he had to give McPherson a day or two to come into line, he set Saturday the 7th of May as the time for the more complete concentration, and an attack upon Tunnel Hill if Johnston should continue to hold it. [Footnote:Id., p. 38.] Accordingly, on Saturday morning all the columns were in motion. Palmer advanced against the ridge of Tunnel Hill in front, and Howard coming from the north turned the flank of the ridge. The hill was held by the Confederate cavalry under Wheeler, supported by Stewart's division of infantry, who were ordered to resist our advance with stubbornness enough to force the display of Thomas's forces. [Footnote: Id., p. 672.] A lively skirmishing fight was kept up till Howard's men advanced toward the flank and rear of the position, when the enemy retreated within Mill Creek Gap. Wheeler was ordered to let a brigade of cavalry retire up the valley of Mill Creek, outside of Rocky Face, and to cover Dug Gap, through which runs the road from Villanow to Dalton. [Footnote: Ibid.]