No. 6. report of Capt. Orlando M. Poe, Corps of Engineers, U, S. Army, Chief engineer, of operations July 1-October 31, 1864.
Washington, D. C., October 8, 1865.Sir: In accordance with the circular from the Engineer Bureau, dated September 2, 1865, I have the honor to report as follows, concerning “the engineer operations and the works of attack and defense conducted under my superintendence during the year ending June 30, 1865 :” This report will naturally be divided into four parts, viz: First. The Atlanta campaign, from the 1st of July, 1864, to the occupation of the city, September 2, 1864. Second. The new defenses of Atlanta and the Savannah campaign, including the time from the 3d of September, 1864, to the 25th of January, 1865. Third. The campaign from Savannah, Ga., to Goldsborough, N. C., from January 25, 1865, to March 22, 1865. Fourth. The campaign from Goldsborough, N. C., to Raleigh, N. C., and the march from Raleigh to Washington City, from April 10, 1865, to 20th of May, 1865. The operations connected with the march of General Sherman's army, extending over a great portion of the Southern States, were of a very rapid character. Such of them as legitimately belonged to the engineer department were so intimately blended with the whole that it is impossible to separate them. In order to explain clearly why bridges were built and roads made in the localities where they were, it will be necessary to give the movements of the army somewhat in detail when the reasons will generally be evident. The labors of the engineers were directed to facilitate these movements, and always with a distinct idea of their object. First. The Atlanta campaign, from the 1st of July, 1864, to the occupation of the city, September 2, 1864. On the 1st of July, 1864, I was on duty as chief engineer with the army commanded by Maj. Gen. W. T. Sherman, then before Kenesaw Mountain, a position to which I had been assigned by Special Field Orders, No. 1, headquarters Military Division of the Mississippi, dated Chattanooga, Tenn., May 3, 1864. At that time the engineer organization for the army in the field was altogether inadequate. There were within the limits of the military division the following engineer organizations, viz: First Michigan Engineers and Mechanics, and First Missouri Engineers. Both these regiments belonged to the Army of the Cumberland, and were distributed as follows:  The former along the railroads forming our lines of supply, engaged in building block-houses to defend them against raiding parties of the enemy's cavalry; and the latter along the important line of railroad from Nashville to Johnsonville on the Tennessee River, engaged in completing that work. The Department of the Ohio was provided with an engineer battalion, organized under my direction in 1863, when the movement upon East Tennessee commenced. Its organization was explained in my report upon that campaign.1 It now accompanied the Army of the Ohio. The De partment of the Tennessee was not provided with any regular engineer organization, but was fortunate in having an excellent pioneer organization. In order to equalize the engineer forces in the military division the major-general commanding, at my suggestion, transferred the First Missouri Engineers from the Department of the Cumberland to the Department of the Tennessee, and it was ordered to join the army in the field. Two pontoon bridges, having an aggregate length of 1,400 feet, were with the forces in the field and distributed as follows: 800 feet, in charge of the Fifty-eighth Indiana Volunteer Infantry, commanded by Col. George P. Buell, were attached to the Army of the Cumberland; 600 feet, in charge of Captain Kossak, aide-de-camp, and a body of pioneers, were attached to the Army of the Tennessee. Both of these bridges were of the kind known as the “canvas bateau bridge.” Two more bridges of the same kind, each 600 feet in length, were held in reserve at Nashville. The staff organization of the engineer department with that army was as follows: Capt. O. M. Poe, U. S. Engineers, chief engineer Military Division of the Mississippi; Capt. C. B. Reese, Corps of Engineers, chief engineer Department and Army of the Tennessee; Capt. W. J. Twining, lieutenant of engineers, chief engineer Department and Army of the Ohio; Lieut. H. C. Wharton, Corps of Engineers, chief engineer Army of the Cumberland. Until the early part of May the duties of chief engineer Army of the Cumberland had been performed by Capt. W. E. Merrill, Corps of Engineers, but he having received authority to organize the regiment of Veteran Volunteer Engineers provided for by act of Congress, had gone to Chattanooga for that purpose. Early in July the following officers of the Corps of Engineers, who had just graduated at West Point, reported to me, and were assigned to duty as follows: Capt. J. W. Barlow, to Army of the Tennessee; First Lieut. O. H. Ernst, to Army of the Tennessee; First Lieut. William Ludlow, to Army of the Cumberland; First Lieut. A. N. Damrell, to Army of the Ohio. In the Army of the Cumberland each corps, division, and nearly every brigade was provided with an officer detailed from among the commissioned officers of the infantry regiments, whose duty it was to make such surveys and reconnaissances as might be wanted. The other two armies were not so well provided, but had sufficient organization to do all that was requisite. The military operations of the previous two months had gradually forced the enemy from his position in Buzzard Roost Gap back to the ground he now held at Kenesaw Mountain. During this time the labors of the engineers were confined to reconnoitering, road making, and bridge building. Pontoon bridges had been built  over the Oostenaula, at Resaca, at Lay's Ferry, and two flat-boat bridges over the Coosawattee; also pontoon bridges over the Etowah River at the cliffs. The enemy showed little disposition to yield his stronghold at Kenesaw. After the assault of the 27th June it was determined to move toward our right, at the same time advancing that flank, a movement which it was supposed would result in the evacuation by the enemy of all ground north of the Ohattahoochee except his bridge-head at the railroad crossing. Receiving instructions from General Sherman, commanding, I made a personal reconnaissance of the ground upon our right as far as our extreme cavalry outposts, at or near Anderson's Mill or Olley's Creek, and immediately upon my return and report the Army of the Tennessee was put in motion. No sooner was this movement developed than the enemy, on the night of the 2d and morning of the 3d of July, evacuated his position at Kenesaw and in front of Marietta, and we took position, the troops moving right on in pursuit. Contrary to expectation and information, we found that the enemy intended to make a stand upon a line from Ruff's Station (Neal Dow) to Ruff's Mill, the flanks being refused along Nickajack and Rottenwood Creeks. This line had been prepared by militia and contrabands only a few days before its occupation by Johnston's army, and was well built, consisting of good infantry parapets, connecting salients, in which were placed a large number of pieces of field artillery in embrasure. The length of this line was nearly six miles. On the 4th of July our skirmishers drove the enemy's into the works on the main road by a spirited dash, being supported by the divisions of Stanley, of the Fourth Corps, and Johnson, of the Fourteenth Corps, and our lines pressed up at all points, but not near enough to silence the artillery. Late in the evening the Sixteenth Corps, forming the left of the Army of the Tennessee, carried by assault a portion of the rebel line. At daylight on the morning of the 5th of July our skirmishers advanced, only to find the enemy gone, a movement rendered necessary upon their part by the success of the Sixteenth Corps on the evening previous. The next linie of works was found in front of the railroad bridge and the several roads and pontoon bridges, at Pace's, Montgomery's, and Turner's Ferries, forming a very extensive tete-de-pont, which consisted of a system of square redoubts, in defensive relations, connected by infantry parapets, but few of these redoubts were prepared for artillery, being arranged with a banquette for infantry fire. The artillery was placed in small intermediate redans. The redoubts partook more of the character of tambours. They were constructed by building double log-pens, and filling the space Between them with earth. There was nothing in the plan to recomnmend them to the attention of the engineers. The left of this line rested upon a large seven-gun redoubt near the mouth of Nickajack Creek, and the right upon another redoubt prepared for eight guns, and situated near the Chattahoochee, about one mile above the railroad bridge. Opposite this point the intrenchments on the south side of the river began, and extended in a continuous line nearly to Island Creek, being altogether about eight miles. The railroad bridge at its southern end was protected by three batteries of irregular shape, and one redoubt. This line, owing to the care bestowed upon its construction and the nature of the approaches, was by far the strongest we  had yet encountered. It had been built for some length of time, and had been located by good engineers. A few days spent in reconnaissances showed us very plainly that it would cost many lives to carry the position by assault, even were an assault to succeed, which was extremely doubtful. It was accordingly deemed best to turn it. An inspection of the country showed us that this must be done by the left, since such a movement to right, owing to the broken character of the country, and the fact that the enemy, expecting us to move that way, had carefully guarded all the crossing-places, was almost impossible. Having decided to pass the river by our left, strong demonstrations were made upon our right to confirm the enemy in the impression that the movement was to be made in that direction, and that we would attempt to cross the river at some point below the mouth of Nickajack Creek. The points selected for the crossing were at Roswell Factory and Phillips' (Isham's) Ferry, and the Army of the Tennessee, which had been demonstrating upon our right, was suddenly thrown to Roswell, where it crossed the Chattahoochee upon a trestle bridge, built by the pioneers of the Sixteenth Army Corps out of the materials at hand. No opposition was made by the enemy. The Army of the Ohio, which had been on the left, now become the center, made a rapid movement across the river at Phillips' Ferry, surprising a small force of the enemy stationed there, and capturing one piece of artillery. While the force which actually effected the crossing was engaged in constructing some light works to serve as a bridge-head, two canvas pontoon bridges were thrown, upon which the balance of the Army of the Ohio crossed. I may make the general remark here that whenever it was deemed necessary to use a bridge for a greater length of time than fortyeight hours the pontoon bridges were invariably replaced by wooden trestle bridges constructed from the materials at hand, either by engineer troops or the pioneer force. The object of this was to preserve the canvas covers of the bateaux, even at the expense of considerable labor, since we had the latter in greater abundance than the former. The canvas bridges at Phillips' Ferry were replaced by a trestle bridge built by the Engineer Battalion of the Twenty-third Army Corps. Another pontoon bridge was thrown meanwhile at Powers' Ferry, some two miles lower down, upon which the Fourth Army Corps crossed. This corps formed a junction with the Army of the Ohio, but the Army of the Tennessee was still acting independently. One division of the Fourth Corps now swept down the south bank of the river to Pace's Ferry, which enabled us to build two pontoon bridges at this point, upon which the Fourteenth and Twentieth Corps crossed. Two days before this the enemy, under influence of the presence of the Fourth and Twenty-third Corps, on the south side of the river, had crossed his whole force to that side, and left us in possession of the strong line on the north side, upon which so much care and labor had been bestowed. The passage of the Chattahoochee had now been completely effected. Our whole army was on the south side of the river, with a loss of less than a dozen men, but between us and Atlanta, our objective, were still the three serious obstacles of Nancy's Creek, Peach Tree Creek. and the entire rebel army. We knew but little about the country, and the inhabitants, always few in number and indisposed to give us information, had all gone farther south. 3Not an able-bodied man was to be  found between Marietta and the enemy's line. We could only feel our way cautiously forward, using the greatest diligence in reconnaissances. The Army of the Tennessee, forming the left wing, was directed toward Stone Mountain; the Army of the Ohio, in the center, toward Cross Keys and Decatur, and the Army of the Cumberland, on the right, via Buck Head, toward Atlanta. The left wing and the center crossed Nancy's Creek the same day, July 18. The cavalry division of General Garrard, which had been operating on the extreme left, succeeded in reaching the Augusta railroad between Decatur and Stone Mountain. On the next day, July 19, the Twenty-third Army Corps, after a sharp skirmish, occupied Decatur, where it formed a junction with the Army of the Tennessee. The Army of the Ohio then withdrew, and passing to the right camped for the night on Pea Vine Creek. The Army of the Cumberland crossed a small force over Peach Tree Creek, which maintained its footing. July 20, the Army of the Tennessee advanced along the Augusta railroad to within about three and a half miles of Atlanta, where the enemy was found intrenched. The Army of the Ohio moved along the road leading from Judge Peyton's to Atlanta, and soon encountered the enemy intrenched. The Army of the Cumberland crossed Peach Tree Creek at several points, and the left of it (Fourth Corps), connecting with the Army of the Ohio, met the same obstacle. The Fourteenth Corps, on the extreme right, moving on the Howell's Mill road, joined the Twentieth Corps on its left, and this, in turn, joined Newton's division,of the Fourth Corps, which was moving on the Collier's Mill road. There was no communication on the south side of Peach Tree Creek between Newton's and the other divisions of the Fourth Corps. This was the status when two rebel corps moving down the Howell's Mill road and Collier's Mill road attacked the Twentieth Corps, together with the left division of the Fourteenth Corps and Newton's division. After a severe engagement, lasting until dark, the enemy was repulsed at all points. The result was to firmly establish our position on the south bank of Peach Tree Creek, having overcome two of the three obstacles already referred to as between us and Atlanta. July 21, we steadily pressed forward along our whole line, developing the enemy in his intrenchments, extending from a point about a mile south of the Augusta railroad around the north side of the city to the Chattanooga railroad. This line was well built, and capable of a tolerably good defense. It consisted of a system of open batteries for artillery connected by the usual infantry parapet, with all the accessories of abatis, chevaux-de-frise, &c. But it was evidently not the main line upon which the enemy relied for his final defense. July 22, the enemy evacuated the line referred to above during the night of the 21st, and we pressed forward on all the roads until the enemy was again found behind intrenchments. Reconnaissances proved that these were finally the main lines of defensive works covering Atlanta. They completely encircled the city at a distance of about one and a half miles from the center and consisted of a system of batteries open to the rear and connected by infantry parapet, with complete abatis, in some places in three and four rows, with rows of pointed stakes, and long lines of chevaux-de-frise. In many places rows of palisading were planted along the foot of the exterior slope of the infantry parapet with sufficient opening between  the timbers to permit the infantry fire, if carefully delivered, to pass freely through, but not sufficient to permit a person to pass through, and having a height of twelve to fourteen feet. The ground in front of these palisades or stockades was always completely swept by the fire from the adjacent batteries, which enabled a very small force to hold them. To this line we opposed another, extending from a point one and a half miles south of the Augusta railroad around by the north to a point one and a half miles southwest from the three-mile post on the Atlanta and Chattanooga Railroad. About noon, while engaged in extending this line to the left and front, the enemy, making a detour to the south and eastward, passed around our left flank and, completely enveloping it, attacked it both in flank and rear. Fortunately the Sixteenth Corps was en route to meet just such an attack, and was in a position to form looking to our left rear, its right joining the Seventeenth Army Corps. The fighting here was of the most desperate character. Meanwhile the enemy pushed one corps from their works right down the Augusta railroad upon our line, where they gained a temporary success, but were finally driven back atlall points. Our troops now were put under the cover of the ordinary rifle trenches, with works of a slightly heavier character for the artillery. Close reconnaissances were made of the enemy's whole line in our front, and it was decided that no attempt at assault should be made upon that part of the enemy's line which we could see. On the 23d of July I talked with the major-general commanding, and from him I learned that no assault would be made at present, neither did he desire anything like regular siege operations, but instructed me to see that the lines occupied by our troops were of such a character that they could be held against a sortie, and to put them forward at all points where it could be conveniently done, at the same time informing me that he would attempt to reach the enemy's line of railroad communication, at or near East Point, the junction of the roads from West Point and Macon to Atlanta. It is about six miles southwest from Atlanta. This movement he hoped would either result in a general engagement, with the chances greatly in our favor, or in the evacuation of Atlanta. He directed me to personally select a line at the Augusta railroad where our left flank could rest and command that road, while the Army of the Tennessee was withdrawn to make the movement indicated. On the morning of the 24th of July, accompanied by Capts. C. B. Reese and J. W. Barlow and Lieutenants Twining and Ernst, of the Corps of Engineers, I passed over the ground, selected the line, and gave the necessary directions for its construction. General Sherman having determined to send a cavalry force around each flank of the enemy to operate upon his communication, I was directed to see in person to the construction of a pontoon bridge at Turner's Ferry. This was done by ordering the train belonging to the Army of the Ten. nessee from where it was then laid, at the railroad crossing over the Chattahoochee, via the old Peach Tree road to Turner's Ferry. After proceeding as far as Proctor's Creek, we found that the enemy occupied Turner's Ferry. It was then too late to do anything toward fighting for possession of the ferry, and I did not have a single armed man with me, even if there had been time. Upon a report of the facts to General Sherman, he ordered the cavalry division of General McCook to clear the ground at daybreak next  morning, July 26, which was done, the bridge constructed, and (communication established between the cavalry forces on the south bank of the river with those on the north bank. The new line to be occupied by our left flank, upon the withdrawal of the Army of the Tennessee, having been completed by the morning of the 27th of July, the movement of that command toward our right flank commenced, and at the same time the movement of the cavalry forces began; that passing around the enemny's left flank being under the command of General McCook, and that around his right flank under Generals Stonemnan and Garrard, the balance of our army meanwhile pressing forward and gaining ground as rapidly as possible. This was continued on the 28th of July, when, at about noon, a furious attack was made upon the Army of the Tennessee, particularly upon the Fifteenth Corps, by a force of the enemy which moved from Atlanta out on the Lick Skillet road. The whole of the Fifteenth Corps had been refused along a ridge extending northwestwardly from Ezra Church, and nearly parallel with the Lick Skillet road, its left joining the Seventeenth Corps and making nearly a right angle with it near the church. The position was a most admirable one, and the enemy was severely whipped. The rebel army in our front had been under command of Joseph E. Johnston until the 19th of July, when the command was transferred to General Hood. Johnston's policy appeared to be a purely defensive one. Hood's was decidedly offensive-defensive, as shown by the fact that three desperate and severe battles were fought, within ten days after he assumed command. The last three days of July were devoted to skirmishing to attain positions as favorable as possible. Meanwhile, under instructions from the major-general commanding, I selected a new line to be occupied as a flank by a portion of the Army of the Cumberland, in case it was decided to transfer the Army of the Ohio to the right flank. The line was constructed under the superintendence of Lieutenant Wharton, U. S. Engineers, after it had been fully, discussed between Lieutenants Wharton, Twining, and myself. It extended from our front line near Walker's house, on the Collier's Mill (Buck Head) road nearly due north, to the line of rebel works evacuated on the night of the 2lst of July. On the night of the 1st of August the Army of the Ohio was withdrawn from its position on the left, and rapidly moved to the right near the poor-house and extending nearly to the north branch of Utoy Creek at Willis' Mill, the engineers giving general directions concerning the lines. I rode over their whole extent in person. August 2, the Army of the Tennessee swung forward its extreme right, about half a mile, turning upon its position at Ezra Church as a pivot. The Army of the Ohio connected with the right of the Army of the Tennessee. This movement developed a part of the enemy's line in front of these two armies, and discovered the same system of batteries, connected by infantry curtains, that we had met before, thus showing that we had not yet found the enemy's left flank, the prime object of all our movements. August 3, a portion of the Army of the Ohio was thrown across .Utoy Creek, and established itself on the south side without much opposition. August 4, an attack was ordered to be made at 3 p. in. by the Army of the Ohio, and the Fourteenth Corps, of the Army of the  Cumberland, the object being to thrust our forces through our lines' and effect a lodgment on the railroad between Atlanta and East Point. The attack, however, was not made. August 5, the Chattahoochee river railroad bridge was completed, and our trains ran up to three-mile post. By General Sherman's direction, I sent Lieutenant Ernst to Marietta to superintend the construction of defenses at that place. An attack was ordered for 2 p. m., the object being as given above, but again no attack was made. August 6, the attack, twice before ordered, was made, but repulsed. The two corps of the Army of the Cumberland, forming the left of our army, kept steadily pushing forward, but without anything like siege approaches. Our sharpshooters had gained such positions as rendered it difficult for the enemy to work his guns. August 7, the attack made yesterday was renewed, and proved successful.. It was found that the line of rifle trenches carried by the assault was not the enemy's main line, but stood nearly perpendicularly to it. The Army of the Tennessee moved forward about 400 yards, swinging upon the center of its right wing as a pivot. The successive advances, either directly or by swing upon some part of the line as a pivot, were made in the following manner-by pushing forward, just before daylight, a strong line of skirmishers to the position chosen beforehand, which maintained its ground during the day, each man getting such cover as he could, generally by scooping out a rifle-pit at the foot of a tree, behind a log or stone, in which they could find shelter. As soon as night made it possible, working parties were thrown out to the skirmish line and connected by the ordinary rifle trenches the entire chain of rifle-pits. These lines were continually being strengthened until it was desired to make another advance, when the operation was repeated. In this way our lines were pushed at any point we wished to within 200 yards of the enemy's and with slight loss. I wish here to impress upon the Engineer Department the fact that nothing like regular siege approaches were attempted. I frequently informed the general commanding that we could easily, at any time, push forward saps and pierce the enemy's lines, yet when we had done so we would have accomplished very little, since the enemy would take the precaution to construct another a few yards in his rear. The general understanding this perfectly always told me that he did not wish anything of the kind done, that he intended to gain possession of Atlanta by operating upon the enemy's lines of communication, until he either brought on a general engagement, in which event he expected to gain a decisive victory, or compel the enemy to evacuate the city, which he could easily do, as the place was not, and it was evident that it could not be, completely invested. August 8 and 9, was at work everywhere strengthening our lines. Commenced the construction of batteries for 4 1/2-inch guns which had been ordered. These were placed in position as follows: Two in front of the Twentieth Army Corps, near the Chattanooga railroad, and two others in front of the Sixteenth Corps. The whole of the Army of the Tennessee advanced about three-eighths of a mile in the manner already described, and the lines of the Army of the Cumberland were straightened, so the whole line was as far advanced as the salients had been. The Army of the Ohio was engaged in intrenching itself in its position south of Utoy Creek. August 10, 11, and 12, no advances were made.  August 13, it was decided to move all the army, except one corps (which was to be thrown back to the Chattahoochee railroad bridge), around Atlanta upon the railroads running south from East Point, and the pontoon train of the Army of the Cumberland was moved from the railroad bridge, along the north side of the river, to the Sandtown Ferry preparatory to throwing a bridge across the river at that point. August 14, nothing was done by the engineer department, waiting further instructions. August 15, the line of Proctor's Creek was examined for the purpose of selecting a defensive flank to be used when the Army of the Cumberland was withdrawn. Two pontoon bridges were laid at Sandtown Ferry. August 16, accompanied by Lieutenants Twining and Damrell, I visited our extreme right and rode over the lines of the Army of the Ohio, as well as the position which Lieutenant Twining had already selected south of Utoy Creek to be occupied by the Army of the Ohio upon the withdrawal of the Armies of the Tennessee and the Cumberland. The position was admirably chosen. A trestle bridge was commenced at Sandtown Ferry to replace the pontoon bridges at that point. August 17, orders for the movement of the army to the rear of East Point were promulgated. The cavalry command of General Kilpatrick started upon a raid to the southward of Atlanta. August 18 and 19, the troops kept hard at work to induce the enemy to believe that we contemplated no movement upon his rear of greater importance than a cavalry raid. The entire force of engineer officers hard at work reconnoitering all the roads to our right as far as the enemy's cavalry would permit. August 20, a force of infantry reached the Atlanta and West Point Railroad near Red Oak Station, and tore up a portion of the track. Our batteries were completed along our whole line and we were ready for any emergency. August 21 and 22, the pioneer force was all kept at work preparing siege materials. The batteries along our whole line kept up a slow but steady fire both upon the enemy's lines and upon the city of Atlanta. The remarks in this paragraph apply to every day for the last two weeks. August 23, under instructions from the major-general commanding, I went to the Chattahoochee railroad bridge and selected a line to be occupied by the corps (Twentieth), which was to be left behind during our movement to the rear of Atlanta, and gave Lieutenant Ludlow full instructions concerning the building of it. The position held by the Fifteenth Army Corps during the battle of the 28th of July was selected by Captain Reese as a flank to be occupied by the Army of the Tennessee upon the withdrawal of the Army of the Cumberland. General Kilpatrick's cavalry command returned, having passed entirely around Atlanta. August 24, at work upon the new flank referred to above. Reconnaissances pushed to the right almost as far as Campbellton. August 25, at midnight the grand movement commenced by the withdrawal of the Fourth and Twentieth Corps. The latter marched directly to the railroad bridge, Pace's and Turner's Ferries, while the former passing in rear of the Army of the Tennessee, bivouacked next night on Utoy Creek. Before the movement began its left had rested on the Decatur road.  August 26, the movement of the Army of the Cumberland still going on, and at dark the left wing of the Army of the Tennessee was swung to the rear upon its right and occupied the position previously prepared for it. August 27, all the army in motion except the Army of the Ohio. The Army of the Cumberland was placed in position along Camp Creek, covering all the roads leading from Mount Gilead Church toward East Point and Red Oak. The Army of the Tennessee was thrown further to the right, but close enough to keep up communication. It covered all the roads leading toward Fairburn. But little resistance was offered to our advance. The troops intrenched their position every night. This was made a rule from the time the campaign commenced, and was continued until the close of the war whenever the proximity of the enemy rendered it prudent. I may add, also, that during all the operations of this great army, extending over a year of time and thousands of miles of territory, it was never surprised. August 28, the Army of the Cumberland was thrown forward upon the Atlanta and West Point Railroad at Red Oak, and the Army of the Tennessee at Shadna Church and Fairburn, while the Army of the Ohio was thrown into such a position along the road from Mount Gilead Church to Red Oak as to cover our left flank. Immediately upon striking the railroad the troops were intrenched and without the loss of a dozen men we had secure hold upon it, and could proceed to destroy it as leisurely as we pleased. August 29, the greater part of the army was at work destroying the railroad, which was effectually done for about twelve and a half miles, every tie being burned and every rail bent. The enemy did not attempt to disturb us. August 30, the army again in motion, being directed as follows: The Army of the Ohio toward Morrow's Mill, the Army of the Cumberland toward Couch's farm-house, and the Army of the Tennessee toward the Renfroe place. The latter pushed on still farther and succeeded in seizing the Flint River bridge and gaining a foothold between the river and Jonesborough. The enemy was found in force, covering the town. August 31, the Army of the Ohio moved toward a point on the Macon railroad two miles south of Rough and Ready Station, and succeeded in reaching it, and, making a secure lodgment, intrenched, The Fourth Corps was put in position in support. Four more brigades of the Army of the Cumberland moved from Couch's due east, until they struck the railroad between the Army of the Ohio and Jonesborough, when they also intrenched. About the same time that these forces reached the railroad the enemy attacked the lines of the Army of the Tennessee immediately in front of Jonesborough and tried to carry them by assault. They were repulsed with heavy loss. It was reported to me by Captain Reese that the First Missouri Engineers, which had been transferred at my request from the Army of the Cumberland to the Army of the Tennessee, had just joined the forces in the field, and were available for duty. This was the first regularly organized engineer regiment to join the army at the front. September 1, the Army of the Cumberland was concentrated so as to connect from the left of the Army of the Tennessee to the railroad, about two miles north of Jonesborough, the Fourth Army  Corps destroying the railroad as it advanced. The Army of the Ohio commenced the destruction of the railroad at Rough and Ready, and connected with the break made by the other troops. About 4 p. m. the Fourteenth Army Corps assaulted and carried the right of the enemy's line, consisting of the usual batteries connected by infantry parapet. The approach of night alone prevented the capture of the entire rebel force. We were now squarely upon the rebel lines of supply. The movements of our army had been so rapid that the enemy exhibited the greatest confusion, and shortly after midnight the light of the burning buildings and explosions of ammunition in the direction of Atlanta (distant twenty miles), indicated very plainly that the enemy was evacuating the place, and on the morning of the 2d of September the Twentieth Army Corps, which had been left behind at the Chattahoochee bridge for the purpose, marched into Atlanta. In describing these operations I have gone somewhat into detail, in order that they might be clearly understood, deeming it peculiarly the province of the engineer to call attention to such brilliant maneuvers as those which enabled us to pass a river, too deep to be forded, in the very face of the enemy with a loss of less than a platoon of men, and those which placed six army corps upon the enemy's lines of communication, in opposition to a single corps. In accomplishing these results the engineer department performed the following special labor, viz: Ten pontoon bridges built across the Chattahoochee River, averaging 350 feet in length, 3,500 feet; 7 trestle bridges, built out of material cut from the bank across the same stream, of which five were double tracked, and two were single, 350 feet long each, 2,450 feet; 50 miles (estimated) of infantry parapet, with a corresponding length of artillery epaulement; 6 bridges over Peach Tree Creek, averaging 80 feet long each, 480 feet; 5 bridges over Flint River, averaging 80 feet long each, 400 feet; also many smaller bridges built and many miles of road repaired. The topographical branch of the engineer department worked efficiently. Surveys were made of all the routes passed over by infantry columns, together with the lines of parapet built. A map on the scale of four inches to one mile illustrating the siege, so called, of Atlanta has been forwarded to the Engineer Bureau, in which these surveys are compiled, from the passage of Peach Tree Creek, July 19, to the beginning of the movement upon the enemy's lines of communication, August 25, and a general map, photographic copy, illustrating the entire campaign from Chattanooga to Atlanta. I have also forwarded to the Bureau, a complete set of photographic views illustrating military operations about Atlanta.2 From the map department 4,000 copies of campaign maps were issued to the proper officers to facilitate military operations. I desire to bear testimony to the efficiency of the engineer officers on duty with General Sherman's army. Though all have done well yet I am particularly indebted to Capt. C. B. Reese and Lieutenants Wharton and Twining. I can only return my thanks to those officers of volunteers who did nearly all the topographical work. They did their duty and did it well. I must leave to the chief engineers of the several armies to which they belonged to do them justice.  Second. The new defenses of Atlanta, and the Savannah campaign, including the time from the 3d of September, 1864, to the 25th of January, 1865. Upon our occupation of the city of Atlanta, acting under instructions from the major-general commanding, I made an examination of the lines occupied by the enemy during the so-called siege, with a view to their modification for the use of our forces. Their development was found to be about twelve miles and was considered greater than could be held by such a force as would, in any event, be left as the garrison. I made further examinations of the ground interior to the old rebel lines to ascertain whether new lines of much shorter development could not be located, and selected the system of heights nearest the center of the city. This line was less than three miles in extent, but passed through the northern part of the town, rendering the destruction of a great many buildings necessary. The general commanding ordered the adoption of this line and directed the work to proceed, but subsequently suspended the operation of the order until greater necessity should arise. Meanwhile every effort was being made to increase the efficiency of the engineer organization. The chief engineer of the Army of the Cumberland was directed to take the necessary steps to have the First Michigan Engineers and Mechanics ordered to the front. This regiment, or rather eight companies of it, arrived at Atlanta about the last of September. Two more companies subsequently joined, but the remaining two companies did not reach the regiment for some months. The major-general commanding having directed that the new line of fortifications be proceeded with, the entire engineer force was set at work to construct the profiles and revetments. General Corse, then commanding at Rome, Ga., on the 29th of September, made an urgent requisition for an engineer officer to examine and improve the defenses of that town. Lieut. William Ludlow, Corps of Engineers, was sent. The first infantry details for work on the fortifications were called for on the 3d of October, and numbered 2,000 men. On the 5th of October I telegraphed to General Sherman, then at Big Shanty, as follows: The new line of works is in a defensible condition from the redoubt where the photographs were taken (Redoubt No. 7) around to the prolongation of the same street eastward. I have positions completely finished this evening for thirty guns; the platforms are laid and the embrasures revetted for that number, and I can finish quite a number more to-morrow. The line represented as in a defensible condition was on the south side of the town and nearly two miles in length; the labor upon it was all done by the two regiments of engineer troops and infantry details from the Twentieth Army Corps, the balance of the army then being in motion against the rebel army, which had appeared upon our lines of communication. Work upon these new defenses continued until stopped, about the 1st of November, though after the first week the details from the infantry commands were much smaller, and the work progressed more slowly owing to this fact, as well as because the impression prevailed that they would not be wanted for our purposes. Much care had [been] bestowed upon the several redoubts, and the finish put upon each was excellent. Those numbered from 7 to 12, inclusive,  were provided with mantelets from the embrasures; these were made both of rope and of boiler iron, and were of such a shape that they completely closed the embrasure when the gun was “from battery.” A complete set of photographs3 illustrating these defenses has been forwarded to the Engineer Bureau, and they are projected upon the map illustrating the siege of Atlanta. 4 All of which is respectfully submitted.