The Siege of Vicksburg: Johnston and Yazoo

The first ground was broken on the 23d of May, and batteries placed in the most advantageous positions to keep down the enemy's fire. Lines of parapet, rifle-trench, and covered way were then constructed to connect these batteries. The enemy seldom showed his guns, hardly attempting, indeed, to prevent the besiegers from getting their artillery into position; for the slightest exposure or demonstration on the part of the rebels excited the liveliest fire from the national batteries, and the advantage was always in favor of the latter, as they could bring to bear a much larger number of guns than the enemy. This, and the remarkable activity and vigilance of Grant's sharp-shooters, in a great measure kept down the fire of the besieged. The enemy, however, was undoubtedly scant of ammunition, and anxious to husband what he had, for more effective use at closer quarters.

The connecting parapets, as well as all other available positions within rifle-range, were kept occupied by a line of sharp-shooters during daylight, and by trench-guards and advanced pickets after dark. Whenever an approach gave opportunity, loop-holes were formed, by piling sandbags and pieces of square timber on the parapets, or logs and stumps when these were more convenient: the men were thus enabled to shelter themselves completely. This timber was rarely displaced by the enemy's fire; but, had the rebel artillery opened heavily, splinters must have become dangerous to the besiegers. The positions of the national sharp-shooters were generally quite as elevated as those occupied by the rebels; and the approaches, running along the hill-sides and up the slopes in front of the enemy's works, were lower than the besieged, so that the sappers and working parties could not be molested by the rebels without very great exposure on their own part to sharp-shooters of the attacking force. So effective was this system that by the end of the first fortnight nearly all the artillery of the enemy was either dismounted or withdrawn, and the rebels scarcely ever fired.

Pioneers and negroes did the greater part of the work, which was mainly left to men ignorant of siege-operations and obliged to depend on their native ingenuity. Yet the Yankee fertility of resource stood the workers in good stead. Gabions and fascines were made of grapevine and split cane, and mortars for close service were made of wooden cylinders with iron bands shrunk on them. The parapets were made but six or eight feet thick, on account of the feeble nature of the enemy's fire, the embrasures being closed, when not firing, by plank shutters or movable timbers. The ground was seared by ravines, rugged and difficult, but this condition aided the rapid advance of the works.

The aggregate length of the trenches was twelve miles. Eighty-nine batteries were constructed during the siege, the guns from those in the rear being moved forward as the siege advanced. The troops were moved on at the same time, and encamped in the rear of batteries, at the heads of ravines. On the 30th of June there were in position two hundred and twenty guns, mostly light field-pieces; one battery of heavy guns, on the right, was manned and officered by the navy. .

While the investment of Vicksburg was thus proceeding, the menacing attitude of Johnston had early attracted Grant's attention, and made it necessary to establish a strong corps of observation in the rear. . . . It was soon learned that Johnston had been joined by at least ten thousand fresh troops; and Grant was thus made reasonably certain that the rebels would endeavor to raise the siege, attacking from the northeast, with all the men they could command. . . . On the 26th [of May] Grant sent a force of twelve thousand men, under Blair, to drive off a body of the enemy supposed to be collecting between the Big Black River and the Yazoo. This command was not expected to fight Johnston, but simply to act as a corps of observation, and to destroy all forage, stock, roads, and bridges as it returned. Blair moved along the Yazoo about forty-five miles, and effectually accomplished the purpose of his expedition, preventing Johnston from moving upon Vicksburg in that direction, and also from drawing supplies in the fertile region between the two rivers. He was absent nearly a week, and reconnoitred the whole region thoroughly.