curse touches the base of these hills at a point 12 miles in the interior known as Snyder's Mill; thence, diverging from them, empties into the Mississippi some 6 miles above the city. There is thus between the hills and the Yazoo a triangular-shaped area of bottom land, densely wooded, with the exception of one or two plantations on it, and intersected with bayous and low, swampy ground. Skirting the hills from Snyder's Mill down to near the Mississippi is first a swamp and then and old bed of the Yazoo, containing considerable water, and only to be crossed without bringing at three points, were torrents from the hills have borne along sufficient matter to fill up the bed. From the termination of this old bed to the Mississippi a belt of timber is felled, forming a heavy abatis. There was thus a continuous obstacle 12 miles long, formed of abatis and water, skirting the base of the hills and but a short distance from them, terminated at one end by our fixed batteries and fortified position at the mill at the other end by the heavy batteries and field-works above Vicksburg. Through this obstacle there are but three natural passages.
It is to be borne in mind that the fortifications proper encircling this city are disconnected and entirely independent of the line described and the one selected on which to meet the enemy. The inquiry naturally arises, Why meet the enemy outside of our fortifications and on a line so extended? The reasons determining were as follows: The Yazoo drains a section of country of great wealth and fertility, has its source in the heart of the State, is navigable at an ordinary stage of water to the Mississippi Central, and has accumulated in its waters a large amount of property in steamboats. All this wealth of products and boats it was important to protect, but still more important to prevent the enemy from getting control of the river, which, once possessed, would give him a base for operations most dangerous to our success. So long as the works at Snyder's Mill were held the whole Yazoo Valley was defended. it was believed those works could be held provided the enemy was forced to make a direct assault upon them from the river and not permitted to disengage himself from the bottom described, break through our line, and, establishing himself in the open country between the mill and Vicksburg, be able to take those works in rear. Another object was also accomplished: The enemy, without gaining the hills, could make no attempt to cut the line of the Vicksburg and Jackson Railroad.
The base of the hills being determined upon as the proper line, preparations were made in advance to guard the three natural approaches to it by throwing up earthworks, felling timber, &c. It was further strengthened during the progress of the attack, as the enemy's plans developed themselves.
Certain information regarding the proximity of the enemy's fleet was first received on the morning of December 23, and by 10 o'clock that night seventy-four transports were known to be in the vicinity of the mouth of the Yazoo, together with some twelve gunboats that had previously arrived. This number was increased during the succeeding two or three days to about one hundred and twenty.
At daylight on the morning of the 25th the troops of the command were ordered in the trenches, which they did not leave again until the attack was abandoned, except to re-enforce different portions of the line as circumstances required.
The 25th and part of the 26th were occupied by the enemy in debarking and making demonstrations of attack at Snyder's Mill, where one of their most formidable iron-clads was very severely handled and driven out of range by the open batteries, under the command of the gallant