HDQRS. 14TH ARMY CORPS, DEPT. OF THE CUMBERLAND, Camp Winford, Tenn., July 8, 1863.

GENERAL: I have the honor to transmit the following report of the operations of the Fourteenth Army Corps from the 24th ultimo to the present time:

The Third Division, Brigadier-General Brannan commanding, having, in accordance with orders previously given, reached Salem from Triune on the 23d, received orders to march with McCook's corps in the direction of Fosterville on the 24th, and on the 25th to join the other divisions of the Fourteenth Army Corps on the Manchester pike. The First Division (Rousseau's), Second Division (Negley's), and the Fourth Division (Reynolds') marched from Murfreesborough June 24, on the Manchester pike, Reynolds' division in advance, starting at 4 a.m., with orders, if possible, to seize and hold Hoover's Gap; Rousseau's division marching at 7 a.m., to move to the support of Reynolds, in case he called upon him for assistance. Negley's division marched at 10 a.m., in reserve. A few miles from our picket station, Wilder's brigade, mounted infantry, Reynolds' division, encountered the enemy's mounted vedettes, which he drove upon their reserve (Third Confederate Cavalry ), and drove the whole through Hoover's Gap and beyond McBride's Creek. Colonel Wilder then observing that the enemy were in force in the direction of Fairfield, and preparing to attack him, took up a strong position on the hills at the southern terminus of Hoover's Gap. The other two brigades of Reynolds moved into and occupied the gap in rear of Wilder's force, and prepared for an attack from the front, having marched 17 miles.

While the division was taking its position, the First Brigade was attacked by a superior force. The attack was promptly accepted by Wilders brigade, supported by the Second and Third Brigades, which were immediately ordered to the front, and posted on the ridge of woods on the extreme right, to prevent the enemy turning our right flank, which was being heavily engaged by a superior force. As these re-enforcements arrived, the enemy was forced to fall back from the woods, and the right made secure by posting three regiments of Crook's brigade in the woods from which the enemy had just been so gallantly driven by the Seventeenth and Seventy-second Indiana Volunteers and Ninety-third Illinois Volunteers, and the position maintained. General Rousseau was ordered to send forward one brigade to re-enforce Reynolds, which was done. Major Coolidge, commanding brigade of Regulars, reported soon after dark, and every preparation was made for an attack on the following morning. The First and Second Brigades of Rousseau's division encamped in supporting distance, near the Widow Hoover's house, and Negley's division at Big Spring, in rear of Rousseau's division. The disposition of General Reynolds' division remained unchanged on the morning of the 25th, with slight skirmishing with the enemy in front. Colonel Scribner's brigade, Second Division, having been ordered to the front in the early part of the day, was posted in position <ar34_431> to support the batteries in front and to form picket line on the extreme left. General Brannan's division, arriving from Salem, was ordered to go into camp near Rousseau, at Hoover's Mill. Orders having been previously given from department headquarters, General Rousseau's division was moved immediately in rear of General Reynolds' division, on the night of the 25th, preparatory to an attack on the enemy's position at Beech Grove. General Brannan's division moved up at 4 a.m. retake part in the attack. General Negley's division moved up at 8 a.m. to support the attack of the other divisions. After carrying the position of Beech Grove, Rousseau's (First) and Brannan's (Third) divisions were ordered to push the enemy in the direction of Fairfield, whilst Reynolds' division was to move along the Manchester pike, seize and hold Matt's Hollow, and push on to Manchester that night, if possible. During the night of the 25th instant it rained so continuously that it became almost impossible for troops to move, but, with extraordinary exertions, the divisions were placed in their respective positions by 10.30 a.m. Immediately after, the advance was ordered, when the enemy were driven steadily and rapidly toward Fairfield; Rousseau and Brannan operating on his left flank from the hills on the north of the Fairfield road, while Reynolds advanced against his front and right. The enemy had evidently prepared for an obstinate resistance, and attempted to enfilade my troops from the high ground on our right, but were effectually prevented by a gallant charge of the First Brigade, Third Division, Colonel Walker, and the Fourth (Regular) Brigade, First Division, Major Coolidge commanding. The steady and rapid advance of my troops forced the enemy to retire in the direction of Fairfield very rapidly, covering his retreat with two batteries of artillery and occupying positions behind strong bodies of skirmishers, flanked by a large cavalry force. The behavior of our troops was admirable--everything that could be desired.

On the morning of the 27th, at 8 o'clock, Reynolds' advance brigade, Wilder's mounted infantry, took possession of Manchester, capturing a guard at the railroad depot and taking the town completely by surprise. Negley's division, marching in support of Rousseau's and Brannan's toward Fairfield, turned into the Manchester and Fairfield road by way of Noah's Fork, and reached Manchester at 8 p.m. Rousseau and Brannan pursued the enemy as far as Fairfield. Ascertaining at that place, from what they considered reliable sources, that the enemy had retreated entirely, these two divisions, in compliance with orders, turned into the Fairfield and Manchester road, Brannan's division reaching Manchester at 10 p.m. and Rousseau's division at 12 midnight. In compliance with department orders, Colonel Wilder, with his mounted brigade, started at reveille on the morning of the 28th, by way of Hillsborough, to break the Chattanooga Railroad at some point below Decherd. The First and Third Divisions started at 2 p.m. in the direction of Tullahoma, camping at Crumpton's Creek, Third Division throwing out a strong party 1½ or 2 miles to its front, toward Tullahoma.

On the morning of the 29th, headquarters and the Second and Fourth Divisions were moved to Crumpton's Creek, the Fourth Division camping at Concord Church, at the point where the road to Tullahoma leaves the Manchester and Winchester road, and relieved the two regiments of Brannan's division on outpost at Bobo's Cross-Roads. The Second Division camped at Bobo's Cross-Roads, where the road from Tullahoma to Hillsborough crosses the Manchester and Winchester road. General Beatty, with his brigade, joining the Second Division at that point from Hillsborough, where he had taken position on the 28th, to support Colonel Wilder in his operations against the railroad, Van Derveer's brigade, from the Third Division (Brannan's), was thrown forward on Tullahoma road, and engaged the enemy's outposts and vedettes, driving them back toward Tullahoma, killing and wounding many; the rebel General Starnes reported among the number killed. Our loss 2 men slightly wounded. Van Derveer's brigade was relieved about 6 p.m. by Steedman's (Second) brigade. The road from Manchester to this point was rendered nearly impassable by one of the heaviest and most continuous rains ever experienced.

June 30, Steedman's (Second) brigade, Third Division, started at an early hour, supported by a brigade from General Sheridan's division on the right and two regiments of Reynolds' division on the left, and pushed forward during the evening to within 1½ or 2 miles of Tullahoma with comparative ease, General Steedman reporting that he was opposed by two regiments of cavalry and one section of artillery, at the same time reporting a loss of 15 men in his command, also killing and wounding many of the enemy, but could not report the number, as they were carried from the field by the enemy. The two regiments of Reynolds' division also reached a point about 2 miles from Tullahoma, where they came upon a regiment of the enemy's cavalry, which retired after feeble resistance. The officer, believing it was intended to lead him into an ambuscade, did not pursue farther. Two regiments from Negley's division moved out on the Manchester road 4 or 5 miles without encountering or seeing the enemy. Colonel Wilder with his brigade returned to-day, having succeeded in striking the railroad and doing considerable damage near Decherd.

Early on the morning of July 1, having heard from a citizen that the enemy were evacuating Tullahoma, Steedman's brigade, Third Division, supported by two regiments of Reynolds' division on his left, were ordered to advance cautiously and ascertain if the report was true. Meeting with no opposition, he entered Tullahoma at 12 m., capturing a few prisoners; General Brannan, commanding Third Division, reporting that the last of the rebel infantry retired during the night, and their cavalry commenced evacuating at daylight. General Reynolds was accordingly ordered to Tullahoma with his division, and the two divisions (Reynolds' and Brannan's) ordered to rejoin the corps at Heffner's Mill on the following morning. General Negley was directed to march to Heffner's Mill, and take post there for the night, General Rousseau to support him. In executing this order, Negley came upon the enemy about 4 miles from Bobo's Cross-Reads, and drove them steadily until they retired just at nightfall beyond Heffner's Mill. He then went into camp for the night, throwing out strong pickets to the right and front. General Rousseau was instructed, after forming his camp, to throw pickets to the rear and left. The enemy made a stubborn resistance through the pass of Spring Creek, wounding a good many of our men, but were steadily driven back until darkness prevented farther pursuit through the thick brushwood bordering the hillsides of the pass.

On the 2d, the Third and Fourth Divisions joined on Spring Creek, and the enemy were followed to the Winchester road crossing of Elk River. The bridges having been burned by the rebels, and the river not fordable, the First, Third, and Fourth Divisions were moved up the river to Jones' Ford, and one brigade of Rousseau's division thrown across the stream, the remainder of the command camping on the north side. The ford being very deep, it was with great difficulty that the brigade effected a passage, damaging much of their ammunition by the water getting into their cartridge-boxes. Colonel Hambright, commanding this brigade, reported that the enemy had left the vicinity of the <ar34_433> ford, and was informed by rebel prisoners that their retreat was by way of Pelham and Cowan, and across the mountains.

On the morning of the 3d, Rousseau's and Brannan's troops crossed the river at Jones' Ford, and took up a position on the Winchester and Hillsborough road, crossing their artillery and trains of both divisions. Negley's division and entire train crossed the ford on the Winchester and Manchester pike. The troops of Reynolds' division crossed at the same place, leaving his ordnance train on the north side of the river, to be crossed in the morning.
On the 4th, Rousseau's division marched to the Decherd and Pelham road, and took up a position at Featherstone's. Negley took up a position at Brakefield Point. Reynolds' division encamped at Pennington's, and Brannan's division at Taite's; the two latter positions on the Decherd, Winchester, and McMinnville road. The order to halt was received at 2 p.m. this day, and the details directed to be made for the repairs of roads were ordered. Location of corps headquarters on the Winchester and McMinnville road, half way between Taite's and Pennington's.

The positions of divisions of my corps are substantially the same to this date.
Without particularizing or referring to individual merit in any one division of my command, I can render willing testimony to the manly endurance and soldierly conduct of both officers and men composing my corps, marching day and night, through a most relentless rain, and over almost impassable roads, bivouacking by the roadside, ever ready and willing to "fall in" and pursue the enemy whenever ordered, with cheerfulness and determination truly admirable, and no less commendable when confronting the enemy; fearless and undaunted, their columns never wavered, giving the highest proof of their veteran qualities, and showing what dependence can be placed upon them in time of peril.

For particulars, incidents, and the part taken by the different divisions, brigades, and regiments of my corps in the engagements mentioned in my report, I respectfully refer you to the accompanying reports of the division commanders.

I am, general, very respectfully, your obedient servant,

 GEO. H. THOMAS,  Major-General U. S. Volunteers, Commanding.

 Brig. Gen. JAMES A. GARFIELD, Chief of Staff, Department of the Cumberland.