Such was the position of affairs, when General Grant took command of these important operations. His first movement was to open a shorter land communication between the Army of the Cumberland and its base of supplies. This was necessary, because the rebels were, substantially, investing Chattanooga; and to lose communication with its base of supplies, would be to lose the army there intrenched. The movement was effected in a very skillful manner, and at considerable peril, by throwing a pontoon bridge across the river Tennessee, at a place called Brown’s Ferry, about one mile and a half by land, and eight miles by water, below the bridge at Chattanooga. The boats for this bridge were floated down from Chattanooga, under cover of the night, and filled with soldiers. More soldiers were then brought across the river at Brown’s Ferry, the enemy was driven back on the hills on the shore, and the bridge was constructed. It was nine hundred feet long, and the work of building it occupied five hours. As soon as this step had been successfully taken, General Hooker moved over from Bridgeport, crossed the river at Brown’s Ferry, and so effected a junction with the forces at Chattanooga. This opened the direct road to Kelly’s Ferry and so to Bridgeport, and effectually baffled the enemy’s hopes of cutting off the Union line of communication. General Grant now pursued, with comparative freedom his campaign for clearing East Tennessee of the armed forces of the Rebellion. The rebel line at this time extended from Lookout Mountain, on the left, to Fort Buckner, the extreme point of Missionary Ridge, on the right. The position was, of course, on the south side of the Tennessee river. The base of supplies was Atlanta. As soon as General Sherman arrived, with his command, from Memphis, General Grant proceeded to carry out his plan of the campaign. The rebel General Longstreet, with a considerable force was now absent from Bragg’s army, having been detached to proceed against the Union troops under General Burnside, at Knoxville. Bragg’s army was, therefore, materially weakened. General Grant was not slow to avail himself of this advantage. The plan upon which he proceeded involved the following detail. A division of General Sherman’s troops was to be sent to Trenton, threatening the enemy’s left flank. Under cover of this movement, General Sherman’s main body was to cross the Brown’s Ferry bridge at night and pass thence into a concealed camp of the north side of the river, opposite South Chickamauga creek. One division was to encamp on the North Chickamauga; about one hundred and twenty pontoons were to be taken under cover of hills and woods, and launched into the North Chickamauga; these were to be filled with men, to be floated out into the Tennessee and down it, until opposite the South Chickamauga (about three miles below), to effect a landing on the bank, and throw up works; the remainder of the command was to be taken