From a point about four miles above Island No. 10 the river flows south three miles, then sweeps round to the west and north, forming a horse-shoe bend of which the two ends are east and west from each other. Where the first horse-shoe ends a second begins; the river continuing to flow north, then west and south to Point Pleasant on the Missouri shore. The two bends taken together form an inverted S [inverted S]. In making this detour, the river, as far as Point Pleasant, a distance of twelve miles, gains but three miles to the south. Island No. 10 lay at the bottom of the first bend, near the left bank. It was about two miles long by one-third that distance wide, and its general direction was nearly east and west. New Madrid, on the Missouri bank, is in the second bend, where the course of the river is changing from west to south. The right bank of the stream is in Missouri, the left bank partly in Kentucky and partly in Tennessee. From Point Pleasant the river runs southeast to Tiptonville, in Tennessee, the extreme point of the ensuing operations.
When Columbus fell the whole of this position was in the hands of the Confederates, who had fortified themselves at New Madrid, and thrown up batteries on the island as well as on the Tennessee shore above it. On the island itself were four batteries mounting twenty-three guns, on the Tennessee shore six batteries mounting thirty-two guns. There was also a floating battery, which, at the beginning of operations, was moored abreast the middle of the island, and is variously reported as carrying nine or ten IX-inch guns. New Madrid, with its works, was taken by General Pope before the arrival of the flotilla.
The position of the enemy, though thus powerful against attack, was one of great isolation. From Hickman a great swamp, which afterward becomes Reelfoot Lake, extends along the left bank of the Mississippi, discharging its waters into the river forty miles below Tiptonville. A mile below Tiptonville begin the great swamps, extending down both sides of the Mississippi for a distance of sixty miles. The enemy therefore had the river in his front, and behind him a swamp, impassable to any great extent for either men or supplies in the then high state of the river. The only way of receiving help, or of escaping, in case the position became untenable, was by way of Tiptonville, to which a good road led. It will be remembered that between New Madrid and Point Pleasant there is a low ridge of land, rising from one to fifteen feet above overflow.