As Grant's army settled into siege lines outside Vicksburg, Mississippi, he re-established his supply line to the north. Grant had briefly cut loose from his supplies in order to pursue his lightning campaign against Jackson, but now that he was on the Mississippi River, he could draw supplies of every kind--ammunition, food, and coffee--while starving the Confederates in Vicksburg of almost all supply.
After the unsuccessful assault of the 22d the work of the regular siege began. Sherman occupied the right starting from the river above Vicksburg, McPherson the centre (McArthur's division now with him) and McClernand the left, holding the road south to Warrenton. Lauman's division arrived at this time and was placed on the extreme left of the line.The Union's ability to control and use the Mississippi River for transportation and supply while denying its use to the Confederacy was a key factor in eventual Union victory.
In the interval between the assaults of the 19th and 22d, roads had been completed from the Yazoo River and Chickasaw Bayou, around the rear of the army, to enable us to bring up supplies of food and ammunition; ground had been selected and cleared on which the troops were to be encamped, and tents and cooking utensils were brought up. The troops had been without these from the time of crossing the Mississippi up to this time. All was now ready for the pick and spade. Prentiss and Hurlbut were ordered to send forward every man that could be spared. Cavalry especially was wanted to watch the fords along the Big Black, and to observe Johnston. I knew that Johnston was receiving reinforcements from Bragg, who was confronting Rosecrans in Tennessee. Vicksburg was so important to the enemy that I believed he would make the most strenuous efforts to raise the siege, even at the risk of losing ground elsewhere.
My line was more than fifteen miles long, extending from Haines' Bluff to Vicksburg, thence to Warrenton. The line of the enemy was about seven. In addition to this, having an enemy at Canton and Jackson, in our rear, who was being constantly reinforced, we required a second line of defence facing the other way. I had not troops enough under my command to man these. General Halleck appreciated the situation and, without being asked, forwarded reinforcements with all possible dispatch.
The ground about Vicksburg is admirable for defence. On the north it is about two hundred feet above the Mississippi River at the highest point and very much cut up by the washing rains; the ravines were grown up with cane and underbrush, while the sides and tops were covered with a dense forest. Farther south the ground flattens out somewhat, and was in cultivation. But here, too, it was cut up by ravines and small streams. The enemy's line of defence followed the crest of a ridge from the river north of the city eastward, then southerly around to the Jackson road, full three miles back of the city; thence in a southwesterly direction to the river. Deep ravines of the description given lay in front of these defences. As there is a succession of gullies, cut out by rains along the side of the ridge, the line was necessarily very irregular. To follow each of these spurs with intrenchments, so as to command the slopes on either side, would have lengthened their line very much. Generally therefore, or in many places, their line would run from near the head of one gully nearly straight to the head of another, and an outer work triangular in shape, generally open in the rear, was thrown up on the point; with a few men in this outer work they commanded the approaches to the main line completely.
The work to be done, to make our position as strong against the enemy as his was against us, was very great. The problem was also complicated by our wanting our line as near that of the enemy as possible. We had but four engineer officers with us. Captain Prime, of the Engineer Corps, was the chief, and the work at the beginning was mainly directed by him. His health soon gave out, when he was succeeded by Captain Comstock, also of the Engineer Corps. To provide assistants on such a long line I directed that all officers who had graduated at West Point, where they had necessarily to study military engineering, should in addition to their other duties assist in the work.
The chief quartermaster and the chief commissary were graduates. The chief commissary, now the Commissary-General of the Army, begged off, however, saying that there was nothing in engineering that he was good for unless he would do for a sap-roller. As soldiers require rations while working in the ditches as well as when marching and fighting, and as we would be sure to lose him if he was used as a sap-roller, I let him off. The general is a large man; weighs two hundred and twenty pounds, and is not tall.
We had no siege guns except six thirty-two pounders, and there were none at the West to draw from. Admiral Porter, however, supplied us with a battery of navy-guns of large calibre, and with these, and the field artillery used in the campaign, the siege began. The first thing to do was to get the artillery in batteries where they would occupy commanding positions; then establish the camps, under cover from the fire of the enemy but as near up as possible; and then construct rifle-pits and covered ways, to connect the entire command by the shortest route. The enemy did not harass us much while we were constructing our batteries. Probably their artillery ammunition was short; and their infantry was kept down by our sharpshooters, who were always on the alert and ready to fire at a head whenever it showed itself above the rebel works.
In no place were our lines more than six hundred yards from the enemy. It was necessary, therefore, to cover our men by something more than the ordinary parapet. To give additional protection sand bags, bullet-proof, were placed along the tops of the parapets far enough apart to make loop-holes for musketry. On top of these, logs were put. By these means the men were enabled to walk about erect when off duty, without fear of annoyance from sharpshooters. The enemy used in their defence explosive musket-balls, no doubt thinking that, bursting over our men in the trenches, they would do some execution; but I do not remember a single case where a man was injured by a piece of one of these shells. When they were hit and the ball exploded, the wound was terrible. In these cases a solid ball would have hit as well. Their use is barbarous, because they produce increased suffering without any corresponding advantage to those using them.
The enemy could not resort to our method to protect their men, because we had an inexhaustible supply of ammunition to draw upon and used it freely. Splinters from the timber would have made havoc among the men behind.
There were no mortars with the besiegers, except what the navy had in front of the city; but wooden ones were made by taking logs of the toughest wood that could be found, boring them out for six or twelve pound shells and binding them with strong iron bands. These answered as cochorns, and shells were successfully thrown from them into the trenches of the enemy.
The labor of building the batteries and intrenching was largely done by the pioneers, assisted by negroes who came within our lines and who were paid for their work; but details from the troops had often to be made. The work was pushed forward as rapidly as possible, and when an advanced position was secured and covered from the fire of the enemy the batteries were advanced. By the 30th of June there were two hundred and twenty guns in position, mostly light field-pieces, besides a battery of heavy guns belonging to, manned and commanded by the navy. We were now as strong for defence against the garrison of Vicksburg as they were against us; but I knew that Johnston was in our rear, and was receiving constant reinforcements from the east. He had at this time a larger force than I had had at any time prior to the battle of Champion's Hill.
As soon as the news of the arrival of the Union army behind Vicksburg reached the North, floods of visitors began to pour in. Some came to gratify curiosity; some to see sons or brothers who had passed through the terrible ordeal; members of the Christian and Sanitary Associations came to minister to the wants of the sick and the wounded. Often those coming to see a son or brother would bring a dozen or two of poultry. They did not know how little the gift would be appreciated. Many of the soldiers had lived so much on chickens, ducks and turkeys without bread during the march, that the sight of poultry, if they could get bacon, almost took away their appetite. But the intention was good.
Among the earliest arrivals was the Governor of Illinois, with most of the State officers. I naturally wanted to show them what there was of most interest. In Sherman's front the ground was the most broken and most wooded, and more was to be seen without exposure. I therefore took them to Sherman's headquarters and presented them. Before starting out to look at the lines—possibly while Sherman's horse was being saddled —there were many questions asked about the late campaign, about which the North had been so imperfectly informed. There was a little knot around Sherman and another around me, and I heard Sherman repeating, in the most animated manner, what he had said to me when we first looked down from Walnut Hills upon the land below on the 18th of May, adding: "Grant is entitled to every bit of the credit for the campaign; I opposed it. I wrote him a letter about it." But for this speech it is not likely that Sherman's opposition would have ever been heard of. His untiring energy and great efficiency during the campaign entitle him to a full share of all the credit due for its success. He could not have done more if the plan had been his own.
On the 26th of May I sent Blair's division up the Yazoo to drive out a force of the enemy supposed to be between the Big Black and the Yazoo. The country was rich and full of supplies of both food and forage. Blair was instructed to take all of it. The cattle were to be driven in for the use of our army, and the food and forage to be consumed by our troops or destroyed by fire; all bridges were to be destroyed, and the roads rendered as nearly impassable as possible. Blair went forty-five miles and was gone almost a week. His work was effectually done. I requested Porter at this time to send the marine brigade, a floating nondescript force which had been assigned to his command and which proved very useful, up to Haines' Bluff to hold it until reinforcements could be sent.
On the 26th I also received a letter from Banks, asking me to reinforce him with ten thousand men at Port Hudson. Of course I could not comply with his request, nor did I think he needed them. He was in no danger of an attack by the garrison in his front, and there was no army organizing in his rear to raise the siege.