The Lafayette and Choctaw, of one thousand tons each, were purchased by the Government and converted into ironclad gunboats with rams. Built deliberately, they were strong and serviceable vessels, but not able to carry as much armor as had originally been intended. They were side-wheel steamers, the wheels acting independently, but had no screws. The Choctaw had a forward turret with inclined sides and curved top, armored with two inches of iron on twenty-four inches of oak, except on the after end and crown, where the iron was only one inch. Just forward of the wheels was a thwartship casemate containing two 24-pound howitzers pointing forward and intended to sweep the decks if boarders should get possession. Over this casemate was the pilot-house, conical, with two inches of iron on twenty-four of oak. From turret to wheelhouses the sides were inclined like casemates and covered with one-inch iron, as was the upper deck. Abaft the wheels there was another thwartship casemate, sides and ends also sloping, in which were two 30-pound Parrott rifles training from aft to four points on the quarter. It had been at first proposed to carry in the forward casemate two guns on a turn-table; but as this did not work, four stationary guns were placed, three IX-inch and one 100-pound rifle, two of which pointed ahead and one on each beam. The Lafayette had a sloping casemate carried across the deck forward, and as far aft as the wheels, covered in the lower part with one inch of iron over one inch of indiarubber; the upper part of the bulwarks had three-quarter-inch plating, and the deck half-inch. She carried two XI-inch bow guns, four IX-inch in broadside but well forward, two 24-pound brass howitzers, and two 100-pound stern guns. The draught of these two boats was about nine feet.
Besides these vessels may be mentioned the Black Hawk, a fine steamer, unarmored, but with a battery of mixed guns, which had been remodelled inside and fitted as a schoolship with accommodations for five hundred officers and men. She carried also syphon-pumps capable of raising any vessel that might sink. The old ram Sampson had been fitted as a floating smithery. The two accompanied the fleet, the former taking her place often in battle and serving as a swift flag-ship on occasions.
Active operations again began toward the end of November, when the rivers were rising from the autumnal rains. The great object of the combined Union forces was the reduction of Vicksburg, upon which the authorities at Washington preferred to move by way of the river, as it gave, under the convoy of the navy, an easy line of communication not liable to serious interruptions. The Confederate line of which Vicksburg was the centre then faced the river, the right resting on Haines's Bluff, a strongly fortified position twelve miles away, near to and commanding the Yazoo; while the left was on the Mississippi at Grand Gulf, sixty miles below Vicksburg by the stream, though not over thirty by land. The place, in the end, was reduced much in the same way as Island No. 10; the troops landing above it on the opposite bank, and marching down to a point below the works. The naval vessels then ran by the batteries and protected the crossing of the army to the east bank. A short, sharp campaign in the rear of the city shut the Confederates up in their works, and the Union troops were able to again secure their communications with the river above the town. There were, however, grave risks in this proceeding from the time that the army abandoned its water-base, adding to its line of communication thirty miles of bad roads on the river bank, and then throwing itself into the enemy's country, leaving the river behind it. It was therefore preferred first to make every effort to turn the position from the north, through the Yazoo country.
MISSISSIPPI VALLEY—HELENA TO VICKSBURG.[ToList]
The Yazoo Valley is a district of oval form, two hundred miles long by sixty wide, extending from a short distance below Memphis to Vicksburg, where the hills which form its eastern boundary again reach the Mississippi. The land is alluvial and, when not protected by levees, subject to overflow in ordinary rises of the river, with the exception of a long narrow strip fifteen miles from and parallel to the eastern border. It is intersected by numerous bayous and receives many streams from the hills, all of which, from the conformation of the ground, find their way first to the Yazoo River, and by it to the Mississippi. The Yazoo is first called, in the northern portion of the basin, the Cold Water, then the Tallahatchie, and, after receiving the Yallabusha from the east, the Yazoo. In the latter part of its course it is a large stream with an average width of three hundred yards, and navigable always, for vessels drawing three feet of water, as far as Greenwood, a distance of two hundred and forty miles. It flows in a southerly direction along the eastern side of the basin, between the hills and the narrow strip of dry land before mentioned, receiving the streams from the former, which it does not touch except at Yazoo City, eighty miles from its mouth. After passing Yazoo City the river makes several successive bends to the west, and then begins to receive the various bayous which have been pursuing their own southerly course on the other side of the strip of dry land, the principal one of which is the Big Sunflower. At the present day the Yazoo enters the Mississippi eight miles above Vicksburg, but formerly did so by another bed, now a blind lead known as the Old River, which diverges from the existing channel about six miles above its mouth.
Neither rivers nor bayous are the simple streams thus described. Separating at times into two or more branches which meet again lower down, having perhaps undergone further subdivisions in the meanwhile, connected one with the other by lateral bayous, they form a system of watercourses, acquaintance with which confers the same advantage as local knowledge of a wild and desolate country. Opposite Helena, in the natural state of the ground is a large bayou called Yazoo Pass, leading from the Mississippi to the Cold Water, by which access was formerly had to Yazoo City; but before the war it had been closed by the continuation of the levees across its mouth.
When not under cultivation, the land and the banks of the streams are covered with a thick growth of timber. Where the troops or gunboats penetrated, it was found that there was abundance of live stock, stores of cotton, and rich harvests of grain. The streams carried on their waters many steamers, the number of which had been increased by those that fled from New Orleans when the city fell; and at Yazoo City the Confederates had established a navy yard, where at least three powerful war vessels were being built for the river service.
The first step by the navy was undertaken early in December, when the autumn rains had caused the rivers to rise. Admiral Porter issued orders, dated November 21st, to Captain Walke to enter the Yazoo with all his gunboats, except the Benton and General Bragg left at Helena, and to destroy any batteries that he could. The object was to get possession of as much of the river as possible and keep it clear for General McClernand, who was to land and make the first attempt on Vicksburg by that way.