from the army at Vicksburg, and also to assign General Grant to the command in Tennessee. As early as September 23d the Eleventh and Twelfth Corps of the Army of the Potomac were detached, and sent under General Hooker to Tennessee, and assigned to protect Rosecrans's line of communication from Bridgeport to Nashville. It was on October 23d that General Grant arrived at Chattanooga, and only in time to save their army from starvation or evacuation. The investment by General Bragg had been so close and their communications had been so destroyed that Bragg was on the point of realizing the evacuation of Chattanooga, which he had anticipated. The report of Grant thus describes the situation on his arrival:
Up to this period our forces in Chattanooga were practically invested, the enemy's lines extending from the Tennessee River, above Chattanooga, to the river at and below the point of Lookout Mountain, below Chattanooga, with the south bank of the river picketed nearly to Bridgeport, his main force being fortified in Chattanooga Valley, at the foot of and on Missionary Ridge and Lookout Mountain, and a brigade in Lookout Valley. True, we held possession of the country north of the river, but it was from sixty to seventy miles over the most impracticable roads to army supplies. The artillery horses and mules had become so reduced by starvation that they could not have been relied upon for moving anything. An attempt at retreat must have been with men alone, and with only such supplies as they could carry. A retreat would have been almost certain annihilation, for the enemy, occupying positions within gunshot of and overlooking our very fortifications, would unquestionably have pursued retreating forces. Already more than ten thousand animals had perished in supplying half rations to the troops by the long and tedious route from Stevenson and Bridgeport to Chattanooga over Waldron's Ridge. They could not have been supplied another week.The first movement under Grant was, therefore, to establish a new and shorter line of supplies. For this purpose a night expedition was sent down the river from Chattanooga, which seized the range of hills at the mouth of Lookout Valley, and covered the Brown's Ferry road. By 10 A. M. a bridge was laid across the river at the ferry, which secured the end of the road nearest to our forces and the shorter line over which the enemy could move troops. General Hooker also entered Lookout Valley at Wauhatchie, and took up positions for the defense of the road from Whiteside's, over which he had marched, and also the road leading from Brown's Ferry to Kelly's Ferry. General Palmer crossed from the north side of the river opposite Whiteside's, and held the road passed over by Hooker. An unsuccessful attack was made on a portion of Hooker's troops the first night after he entered the valley. Subsequently we lost the remaining heights held by us west of Lookout Creek.