Tuesday, December 1.-The Engineer Battalion and contrabands at work. A line of rifle-trenches was located across the gorge between Temperance Hill and Mabry's Hill, and a portion of it completed. The troops on the south side of the river were hard at work with all the tools we had to spare from the north side. During the afternoon large trains belonging to the enemy were seen to move toward the eastward, and the belief began to grow upon us that the siege would be raised.

Wednesday, December 2.-The Engineer Battalion and contrabands were particularly engaged in the rifle-trenches between Temperance Hill and Mabry's Hill and an epaulement for two guns in the gorge. These were all finished by midnight. Still at work on large fort at Bell's house and on rifle-trenches on south side of the river. Everything unusually quiet for the fifteenth day of a siege. Thursday, December 3.-Still hard at work on both sides of the river. A disposition apparent among the troops to consider their position strong enough to repel any assault the enemy might make, and a consequent indisposition to work. Evidently but a small force of the enemy east of the Tazewell road. The enemy's trains seen moving to the eastward.

Friday, December 4.-Still working a little, but the news of approaching re-enforcements and the movements of the enemy's trains lead us to believe that he will soon abandon the siege.

Saturday, December 5.-The siege of Knoxville terminated by the retreat of the enemy in the direction of Strawberry Plains (eastward). Heavy re-enforcements for us reached the south side of the river.

The enemy's infantry, or at least that part of it belonging to Longstreet's own corps, left in a solid body very deliberately, no signs of haste being apparent. The rear guard of his column passed the Tazewell road about 7 a. m.

A feeling of intense satisfaction pervaded the whole command, and many persons assured me of their conversion to a belief in "dirtdigging." It certainly proved efficient here. Examined the enemy's late position, and was surprised to find so little evidence of good engineering. I saw positions for only eighteen guns on the north side of the river, but could not discover that more than twelve of them had been used. Any other artillery he used was without cover. The topography of the vicinity of Knoxville may be briefly described as follows: On the north bank of the river a narrow ridge is formed, extending from a point about 2 miles east of Knoxville to Lenoir's. It has an average base of about 1 miles in width. At Knoxville the width is about 1 mile. This ridge is cut through at short intervals by small streams, two of which, First and Second Creeks, run through the town of Knoxville at a distance from each other of about three-quarters of a mile. The main part of the town is built upon that portion of the ridge bounded on the northwest by the valley; on the southwest by Second Creek; on the southeast by the Holston River, and on the northeast by First Creek. It has the appearance of a table, elevated about 150 feet above the river and about 100 feet above the valley. Again, Third Creek is found about seven-eighths of a mile below Second Creek, forming a second similar table. A depression in the ridge about the same distance east of First Creek forms still another table, upon which is built East Knoxville. This elevated ground is called Temperance Hill. From this eastward the ridge is more broken until it disappears, and other

ridges spring up. This last division is known as Mabry's Hill, and is the highest ground by some 20 feet to be found on the north side of the river within cannon range of Knoxville.

Commencing at Third Creek and going eastward, these tables may be numbered 1, 2, 3, and 4. A succession of ridges, all parallel to the one alluded to above, are found at short distances apart as one goes back from the river, the most important of which is at an average distance of 1 mile from the one Knoxville is situated upon, and is that which the enemy occupied. As near as can be ascertained by a pocket level, its elevation is exactly that of table No. 1 at its highest point. In selecting lines it was my opinion that tables Nos. 1, 2, 3, and 4 should be occupied. In this opinion the general commanding concurred, except regarding No. 4. It was a question whether it was most prudent, with our small force, to attempt to occupy No. 4 or to limit our occupation in force to Nos. 1, 2, and 3, simply holding No. 4 with a strong outpost. It seemed to me that we could (as we did) construct lines on No. 4 and also on No. 3, those on No. 4 to be thrown so far to the front that they could not be made available against us in event of their capture by the enemy and to be held by us with obstinacy, only leaving them when absolutely compelled to do so, in which case the lines on No. 3 would form our defense, and the enemy, after a stubborn fight, in which he would have suffered, would only have occupied a position, from which, in the former case, it would have been necessary to dislodge a mere outpost. In other words, after crippling him all we could in his successful assault upon No. 4, we would still have just as good a defense as if we had occupied No. 3 in the first place. But, on the other hand, by extending our lines to include No. 4, we made them weak in numbers at any one point, and we were consequently exposed to greater danger of being successfully assaulted along our whole position. This difficulty was partially obviated by the successful construction of a dam across First Creek, by which an impassable water obstacle of three-quarters of a mile in length was made immediately in front of and parallel to the crest of No. 3, which enabled us to greatly weaken our numbers (of infantry) on that part of the line. The general commanding yielded to my opinion, and all the foregoing positions were occupied as follows: On No. 1, Forts Sanders and Byington and Batteries Noble and Zoellner; on No. 2, Fort Comstock and Batteries Galpin, Wiltsie, and Billingsley; on No. 3, Fort Huntington Smith and Batteries Clifton Lee, Fearns, and Stearman; on No. 4, Fort Hill. All our works were connected by a continuous line of rifle-trenches. Between the ridge occupied by ourselves and that occupied by the enemy the valley varied in width, but its average breadth was in the neighborhood of 1 mile. It was almost entirely cleared of timber, and was at every point under the fire of our artillery. A direct advance over it would have been made only with serious loss. This would have been particularly the case in front of No. 4, where the valley widened to 1 miles and was without timber or cover of any kind for troops. On the south side of the river the ground rises into a series of prominent points, the highest of which is about 350 feet, and is directly opposite Knoxville, the prolongation of Gay street passing directly over it. These knobs formed a range quite close to the river bank, with a wide valley beyond them. It was all important to us that at least three of these knobs should be held. We actually held four of them, commencing with the first hill east of the Louisville road and counting down the

river. As already stated, the enemy made several attempts to get possession of these heights, the first being made on Sunday, November 15, by a heavy force of cavalry, under the command of Wheeler, which was repulsed by Sanders' division of cavalry, which had been guarding the right bank of the Little Tennessee, and had gradually fallen back before Wheeler's heavier force. Sanders was assisted by Cameron's brigade of infantry. From these heights an artillery fire can be delivered in front of each flank of the lines on the north side of the river. Commencing with the most easterly hill (which we called Sevierville Hill) and numbering them 1, 2, 3, and 4, our works were as follows: On No. 1, only rifle-trenches; on No. 2, Fort Stanley; on No. 3, Fort Dickerson; on No. 4, Fort Higley. Nos. 1 and 2 were connected by rifle-trenches, while Nos. 3 and 4, though not connected, each was well provided with rifle-trenches to cover the infantry supports of the batteries. With sufficient time this disposition could be very much improved by making the several forts of such a character (building bomb-proofs for stores and cisterns for water) that each would be self-reliant.

That

The siege of Knoxville passed into history. If mistakes were made in the defense, they were covered by the cloak of success. many were made in the attack was apparent to us all. That the rebels made a great error in besieging is as evident as it now is that to accept siege at Knoxville was a great stroke of military policy. The results of the successful defense are: the defeat of Bragg's army and consequent permanent establishment of our forces at Chattanooga, with tolerably secure lines of communication; the confirmation of our hold upon East Tennessee; the discomfiture of and loss of prestige by the choicest troops of the enemy's service.

There is no language sufficiently strong which I can use to express admiration of the conduct of our troops. From the beginning of the siege to the end every man did his whole duty. The cheerful looks and confident bearing which met us at every turn made it seem as though we were sure of victory from the first. It is doubtful whether any man within our lines had at any time after the first forty-eight hours any fear of the result. All privations were borne, all hardships undergone with a spirit which indicated as plainly as if written on the walls that success would attend our efforts. And is there any man of that part of the Army of the Ohio which was in Knoxville who would exchange his nineteen days of service there for any other of the achievements of his life? Was there a regiment there which will not put Knoxville as proudly on its banners as they now bear Roanoke or New Berne, Williamsburg or Fair Oaks, Chantilly or South Mountain, Antietam or Vicksburg?

The troops of the Ninth Army Corps, and of the Twenty-third, were chivalric rivals where duty was to be done. Never had an engineer officer less cause to complain of the manner in which his instructions and directions were carried out. And here I feel it my duty to refer to the great value of the services of the contrabands. Tractable and willing (many of them came to me and volunteered to work), they did an amount of work which was truly astonishing. Day and night they worked without a murmur. For the first week they labored regularly eighteen hours out of the twenty-four, and during the whole siege, out of nearly 200 that we had at work, only 1 asked to be excused, and he for only one afternoon.

The question of supplies during the siege was second to none in importance. The failure of the enemy to close, the Sevierville road

and French Broad River enabled us even to accumulate a quantity of commissary stores. I was told that it was officially reported at the beginning of the siege that we had on hand full supplies for only one day and a half. Yet, after nineteen days' siege, we had accumulated to such an extent, over lines just referred to, that we had provisions enough to last ten days. The cavalry force was at once sent in pursuit of the retreating enemy, and during the day sent in quite a number of prisoners.

On Monday, December 7, all the available infantry force of the Army of the Ohio was put in motion toward the enemy, and followed him slowly until the 9th, when our forces halted-the cavalry at Bean's Station and the infantry at Rutledge. The enemy had halted at or near the Red Bridge, between Beans Station and Rogersville. No attack was made by us, as the enemy was still in vastly superior force.

On the 11th, Major-General Burnside, having been relieved by Major-General Foster, left for the North, and that properly fixes the close of this report.

To Lieut. Col. O. E. Babcock, assistant inspector-general of the Ninth Army Corps, and captain of Engineers, I'am under very heavy obligations. Always ready with the most practicable advice, he cheerfully gave it, and it never passed unheeded. To Maj. Ś. S. Lyon, Fourth Kentucky Cavalry, and assistant engineer, I am under obligations for valuable reconnaissance. It is a matter of regret that the age and failing health of this officer impairs to a certain extent his usefulness as a topographer, for which branch of science he has such a wonderful talent. Capt. C. E. McAlester, Twentythird Michigan Infantry, acting as chief engineer of the Twentythird Army Corps; Capt. G. W. Gowan, Forty-eighth Pennsylvania Volunteers, assistant engineer of the Army of the Ohio; Čapt. O. S. McClure, Fiftieth Ohio Volunteer Infantry, in command of the Engineer Battalion, rendered important assistance.

The Engineer Battalion proved almost invaluable. Its members were always ready to work, day or night, and did it with an intelligence which directed the labor toward a result. My thanks are due, and are freely given, to its officers and men.

All of which is respectfully submitted.

ORLANDO M. POE,

Captain, U. S. Engs., Chief Engineer, Army of the Ohio.

Maj. Gen. AMBROSE E. BURNSIDE,
Commanding Army of the Ohio.

HDQRS. MILITARY DIVISION OF THE MISSISSIPPI,

CHIEF ENGINEER'S OFFICE,
Nashville, Tenn., April 11, 1864.

SIR:* Meanwhile, I had dispatched Asst. J. H. Brooks to Loudon, with instructions concerning defensive works at that point. He had been directed to make a survey of the road from Knoxville to Loudon, which I had decided to adopt as the base of surveys on thẹ· peninsula included between the Clinch and Holston Rivers, and extending as far to the eastward as Strawberry Plains. The subse

For part (here omitted) covering operations in East Tennessee from August 12 to October 10, 1863, see Series I, Vol. XXX, Part II, p. 568.

quent active military operations defeated this part of my plans, though the data on hand will enable me to make a tolerably good map of the territory alluded to.

On the 23d October, I accompanied the general commanding to Loudon, where the ground was thoroughly reconnoitered, and on Tuesday, October 27, after two strong reconnaissances in the direction of the Sweet Water, it was decided to evacuate Loudon, not because it was untenable, but in order to adopt another line much more favorable.

This was the line of the Tennessee from Kingston to Lenoir's, where a pontoon bridge was to be thrown over the Holston, thence, by the right bank of the Little Tennessee River, to a point sufficiently near the mountains to render a movement by the enemy around that flank impracticable. This line required a much smaller force to hold, particularly as the autumn rains were coming on, when the Little Tennessee would not be fordable.

The wisdom of this movement became apparent to those who had misunderstood it, when Longstreet made his advance upon Knoxville in two columns (infantry) by the way of the Kingston road, and a heavy cavalry force via Maryville, having for its object to seize the heights on the south side of the Holston opposite Knoxville. We all have a lively and grateful remembrance of the beautiful manner in which this latter movement was thwarted, by that very force which had been guarding the right bank of the Little Ten

nessee.

By direction of the general commanding I took up the pontoon bridge at Loudon, on the morning of the 28th October, immediately after the troops had crossed it, and transported it to the railroad track at the east end of the Loudon bridge, whence the boats, forty in number, the chess, and a part of the anchorage, after being loaded upon the cars, were carried to Knoxville. This occupied the limited transportation of the railroad for two days, so that it was not until 1 o'clock p. m. of Sunday, November 1, that the bridge was finally in a condition to permit Sanders' division of cavalry, with its baggage, to cross on it from Knoxville to the south bank of the river. The bridge was thrown across the river at the mouth of First Creek.

The transportation and reconstruction of this bridge, while it involved no great skill, did require an immense amount of hard labor; but the usefulness of the bridge has been so great that a hundred times as much would have been well spent.

The bridge across the Holston, at Lenoir's, was successfully constructed out of the material at hand, by Lieutenant-Colonel Babcock, assistant inspector-general, of the Ninth Army Corps. was destroyed by ourselves in the subsequent operations.

It

About this time I received orders to build a pontoon bridge which could be transported upon the ordinary army wagons. There was absolutely nothing prepared in the way of material. The lumber was standing in the woods, and the nails were lying around the railroad shops in the shape of scraps of old iron. Blacksmiths were at once set at work transforming the scraps into nails; and the sawmills to sawing the lumber. Unfortunately, the saw-mills under my control were sadly out of repair, and it was only after the most vexatious delays, on account of broken machinery, that we were able to get even a small portion of the lumber together.

A part of the Engineer Battalion was at work upon the bridge