Creek, make deep ravines, which leave a series of ridges, very irregular in outline, but generally parallel to the river. About half a mile below the mouth of Indian Creek, Hickman Creek, flowing eastwardly, empties into the river at right angles with it. Small branches running into Hickman Creek almost interlock with those emptying into Indian Creek, whereby the series of ridges parallel to the river are made to extend continuously from the valley of one creek to the valley of the other.

Fort Donelson, a bastioned earthwork, was erected on the river-bluff, between the two creeks, its elevation being one hundred feet above the water. A bend in the river gives the fort command over it as far as its armament could carry. On the slope of the ridge facing down stream, two water-batteries were excavated. The lower battery and larger one, was so excavated as to leave traverses between the guns. A ten-inch columbiad and nine thirty-two pound guns constituted the armament of the lower battery; a rifled piece, carrying a conical ball of one hundred and twenty-eight pounds, with two thirty-two pound carronades, the armament of the upper. These water-batteries were, according to Colonel J.D. Webster, General Grant's chief of staff, thirty feet above the water-level at the time of the attack. Colonel Gilmer, the engineer who constructed them, reported them as being fifty feet above the water-level; but it does not appear at what stage of the water. As the narrow channel of the river allowed an attacking party to present only a narrow front, the batteries required but little horizontal range for their guns, and the embrasures were accordingly made quite narrow. Eight additional guns were in the fort.

Colonel Gilmer, going from Fort Henry to Fort Donelson, immediately began the tracing and construction of works for infantry defence. The river protected the east face of the position, and the valley of Hickman Creek, filled with back-water from the river, sufficiently guarded the north. The line traced was two miles and a half long, following the recessions and salients. The right of the line, occupying a ridge extending from creek to creek, was nearly parallel with the river, and distant from it fourteen hundred yards in an air-line. It was somewhat convex, projecting to the front about its centre, at the point where Porter's battery was afterward posted. The left, facing to the south and southwest, beginning just above Dover, on the point of a ridge extending nearly to the river between the two small brooks, continued out from the river along this ridge to its western extremity, and thence across the valley of the small curved stream described as encircling Dover and emptying into Indian Creek, to a V-shaped eminence in the fork between this small stream and Indian Creek. This salient termination was on the continuation of the line of the right or the west face of the infantry works. This point was assigned to Maney's battery and Heiman's brigade. The line of infantry defence was what came to be called, during the war, rifle-pit—a trench with the earth thrown up on the outer side. Batteries were constructed at nine points in the line, and armed with the guns of eight field batteries.

The Line from Columbus to Bowling Green.

The valley of Indian Creek made a break in the line; there was an interval at the creek between the portion occupied by Heiman's line and the work on the opposite slope, afterward the extreme left of General Buckner's command. The entire line on both faces, except the portion crossing the small valley or ravine to Heiman's left, followed the face of ridges from fifty to eighty feet high, faced by valleys or ravines filled with forest and underbrush. The trees were cut about breast-high, and the tops bent over outward, forming a rude abattis extremely difficult to pass through. The back-water filling the valley of Hickman Creek was an advantage to the defenders of Donelson, in so far as it served as a protection to one face of the position, and diminished the distance to be guarded and fortified. It was quite as great an advantage to the besiegers as it was to the besieged. They were by it relieved from a longer, being an exterior, line. Their transports and supplies could be landed and hauled out in security. Moreover, the back-water extending up Indian Creek also, within the defensive lines, cut the position in two, and made communication between the two parts inconvenient.

Immediately upon the capture of Fort Henry, work was begun on this line of infantry defence. The garrison, increased by the force from Fort Henry, numbered about six thousand effective men, under the command of Brigadier-General Bushrod R. Johnson. General Pillow, ordered by General A.S. Johnston, arrived on February 9th from Clarksville with 2,000 men. He was immediately followed by General Clarke, who had been stationed at Hopkinsville with 2,000 more; and Generals Floyd and Buckner, who were at Russellville with 8,000 more, followed. General Johnston began to set them all in motion by telegram from Bowling Green, before he received news of the surrender of Fort Henry. General Floyd was so averse to going to Donelson that he continued to remonstrate. General Buckner, whose division had arrived, proposed on the night of the 11th to take it back to General Floyd, his commanding officer at Clarksville; but Pillow, who was senior to Buckner, ordered him to remain, and repaired himself to Clarksville. Under the combined influence of Pillow's persuasion and General Johnston's orders, Floyd finally made up his mind to go, and arrived at Donelson with the last of his command in the night of the 12th. Meanwhile, Major-General Polk had sent 1,860 men from Columbus. On the night of February 12th, Donelson was defended by about 20,000 men. The heavy guns in the water batteries were manned mostly by details from light batteries and artillery drilled a short time before the national force appeared, by two artillery officers, under the supervision of Colonel Milton A. Haynes, Chief of the Tennessee Corps of Artillery.

General Grant, in reporting to General Halleck, on February 6th, the surrender of Fort Henry, added: "I shall take and destroy Fort Donelson on the 8th, and return to Fort Henry." It was soon clear that he could not haul wagons over the road, and he proposed to go without wagons and double-team his artillery. The water continued rising. For two miles inland from Fort Henry the road was for the greater part under water. On the 8th he telegraphed: "I contemplated taking Fort Donelson to-day with infantry and cavalry alone, but all my troops may be kept busily engaged in saving what we now have from the rapidly rising water." The cavalry, however, fording the overflow, went to the front of Donelson on the 7th, skirmished with the pickets, and felt the outposts.

General Halleck went earnestly to work gathering and forwarding troops and supplies. Seasoned troops from Missouri, and regiments from the depots in Illinois, Indiana, and Ohio—so freshly formed that they had hardly changed their civil garb for soldier's uniform before they were hurried to the front to take their first military lessons in the school of bivouac and battle—were alike gathered up. General Halleck telegraphed Grant to use every effort to transform Fort Henry into a work strong on its landward side, and by all means to destroy the railroad bridge across the Cumberland at Clarksville, above Fort Donelson. Grant was urging Commodore Foote to send boats up the Cumberland to co-operate in an attack on Donelson.

On February 11th, Foote sailed from Cairo