ON Saturday morning, December 27th, the advance of the “right wing of the Army of the Tennessee” reached Vicksburg. The approach to the city from Johnston’s Landing was very difficult, the town “being on a hill, with a line of hills surrounding it at a distance of several miles, and extending from Haines’ Bluff, on the Yazoo River, to Warrenton, ten miles below, the city, on the Mississippi River. The low country in the vicinity is swampy, filled with sloughs, bayous, and lagoons; to approach Vicksburg with a large force by this route, even in times of peace, would be a matter of great difficulty, and with an enemy in front, it was almost an impossibility.” The line of battle was soon formed by the army, and, from different points, the onset made upon the enemy’s works. Oh! how gallantly those Western legions beat against the ramparts! And when the twilight shadows stole over the bristling walls and hill-sides, they had driven the rebel forces a mile from their original position. Sunday dawned upon the night’s repose of the combatants, and on the sacred air rang out the summons to carnage again. But the affair at Holly Springs had broken up the grand plan of attack, while the flying troops from General Grant’s front reënforced the garrison. Over the battlements of rebellion poured the iron tempest upon Sherman’s unyielding lines. Securely the foe remained behind those defences, rising for two miles along the bluff, presenting a barrier no army small as the “right wing” could scale or remove. Meanwhile the sharpshooters from the forest dropped the officers on every hand. The brave Sherman was all the while expecting every moment to hear the roar of General Grant’s guns in the rear. With Monday came a succession of brilliant charges, which were fruitless as the dash of sunlit waves against the cannon-pierced granite of Gibraltar. If a momentary advantage were gained, it was lost in the return tide of overwhelming numbers. A spectator of these terribly sublime encounters, wrote: “General Morgan, at eleven o’clock A. M., sent word to General Steele that he was about ready for the movement upon the hill, and wished the latter to support him with General Thayer’s brigade. General Steele accordingly ordered General Thayer to move his brigade forward, and be ready for the assault. The order was promptly complied with, and General Blair received from General Morgan the order to assault the hill. The artillery had been silent for some time; but Hoffman’s battery opened when the movement commenced. This was promptly replied to by the enemy, and taken up by Griffith’s First Iowa battery, and a vigorous shelling was the result. By the time General Blair’s brigade emerged from its cover of cypress forest, the shell were dropping fast among the men. A field-battery had been in position in front of Hoffman’s battery; but it limbered up and moved away beyond the heavy batteries and the rifle-pits.