General Hunter immediately took up the offensive, and moving up the Shenandoah valley, met the enemy on the 5th of June at Piedmont, and after a well-contested battle of ten hours, routed and defeated him, capturing on the field of battle one thousand five hundred men, three pieces of artillery, and three hundred stand of small arms.

On the 8th of the same month Hunter formed a junction with Crook and Averill at Staunton, from which place he moved direct on Lynchburg, via Lexington, which place he reached and invested on the 16th day of June. Up to this time he was very successful, and but for the difficulty of taking with him sufficient ordnance stores over so long a march, through a hostile country, he would no doubt have captured that, to the enemy, important point. The destruction of the enemy’s supplies and manufactories was very great. To meet this movement under General Hunter, General Lee sent a force, perhaps equal to a corps, a part of which reached Lynchburg a short time before Hunter. After some skirmishing on the 17th and 18th, General Hunter, owing to a want of ammunition to give battle, retired from before the place. Unfortunately, this want of ammunition left him no choice of route for his return but by way of Kanawha. This lost to the country the use of his troops for several weeks from the defence of the north; at a period, too, when they were urgently needed.

Had General Hunter moved by way of Charlottesville, instead of Lexington, as his instructions contemplated, he would have been in a position to have covered the Shenandoah valley against the enemy, should the force he met have seemed to endanger it. If it did not, he would have been within easy distance of the James river canal, on the main line of communication between Lynchburg and the force sent for its defence. General Grant says: “I have never taken exception to the operations of General Hunter and I am not now disposed to find fault with him, for I have no doubt he acted within what he conceived to be the spirit of his instructions and the interest of the service. The promptitude of his movements and his gallantry should entitle him to the commendation of his country.”

As soon as it was ascertained by the enemy that General Hunter was retreating from Lynchburg by way of the Kanawha river, thus laying the Shenandoah valley open for raids into Maryland and Pennsylvania, he returned northward, and moved down that valley. When this movement of the rebels was ascertained, General Hunter, who had reached the Kanawha river, was directed to move his troops without delay, by river and railroad, to Harper’s Ferry; but owing to the difficulty of navigation by reason of low water and breaks in the railroad, great delay was experienced in getting there. It became necessary, therefore, to find other troops to check this movement of the enemy. For this purpose General Grant detailed the Sixth corps, taken from the armies operating against Richmond, to which was added the Nineteenth corps, then fortunately beginning to arrive in Hampton Roads from the Gulf department, under orders issued immediately after the result of the Red river expedition had become known. The garrisons of Baltimore and Washington were at this time made up of heavy artillery regiments, hundred-days’ men, and detachments from the invalid corps. One division under command of General Ricketts, of the Sixth corps, was sent to Baltimore, and the remaining two divisions of the Sixth corps, under General Wright, were subsequently sent to Washington.

On the 3d of July the enemy approached Martinsburg. General Sigel, who was in command of the Federal forces there, retreated across the Potomac at Shepardstown; and General Weber, commanding at Harper’s Ferry, crossed the river and occupied Maryland heights. On the sixth, the enemy occupied Hagerstown, moving a strong column towards Frederick city. General Wallace, with Rickett’s division and his own command, the latter mostly new and undisciplined troops, pushed out from Baltimore with great promptness, and met the enemy in force on the Monocacy, near the crossing of the railroad bridge. A spirited engagement took place, but owing to the inferiority of General Wallace’s command in numbers and discipline, he was unable to withstand the rebel army, and the Federal arms suffered defeat. An important result was gained, however, for the rebel army was checked in its onward march, and sufficient time gained to enable General Wright, with two divisions of the Sixth corps, and the advance of the Nineteenth corps to reach Washington, and guard the national capital from the peril which was threatening it. General Wallace was warmly commended by the commander-in-chief, for his courage and promptness in meeting the enemy at that important crisis.

Great alarm was now manifested in Baltimore and Washington, which was heightened by the daring and success of numerous raiding parties from Early’s command, who spread themselves in all directions, carrying off horses and cattle, and levying contributions from the inhabitants. Darnestown, in Maryland, was visited by one party, and Brestown, sixteen miles from Baltimore, by another. A third party swept round Baltimore, inflicting damage on the Northern Central railroad, while a fourth reached the Baltimore and Philadelphia railroad, stopped the train, and robbed the passengers, capturing Major-General Franklin, who was a traveller in citizen’s dress. The house of Governor Bradford, of Maryland, within five miles of Washington, was burned by Early’s soldiers.

From Monocacy, General Early, the Confederate chief, marched direct for Washington, his cavalry advance reaching Rockville on the evening of the 10th. General Wright, who had now reached the outer defences of Washington, was placed in command of all the forces that could be made available to operate against the enemy in the field, and made preparations to advance and meet Early, with the design of forcing him to battle, or of pursuing him as far as prudence would warrant.

A reconnoissance was thrown out from Fort Stevens on the 12th of July, and the enemy was soon discovered in force. A short but severe engagement ensued in which only a small portion of the Union forces were engaged; but the enemy were soon put to flight, and Early commenced a retreat, vigorously pursued by the Federal troops. The Union loss in this engagement was about two hundred and eighty in killed and wounded; while the rebel loss was probably somewhat greater. On the 13th a portion of Early’s forces were overtaken at Snicker’s Gap, where a sharp skirmish occurred. On the 20th, another portion of the rebel army was confronted at Winchester, by General Averill’s command, in which the enemy was engaged and defeated, with the loss of several hundred prisoners and four pieces of artillery.

The protracted absence of General Hunter’s corps on his unsuccessful expedition to Lynchburg, encouraged the rebel forces in the valley to attempt another raid into Maryland and Pennsylvania. The enemy moved down the valley, and on the 30th of July, a raiding party burned Chambersburg in Pennsylvania, and then retreated towards Cumberland, pursued by the Federal cavalry. Near that point they were met and defeated by General Kelly, and then, with diminished numbers, they made their escape into the mountains of Western Virginia.

During the whole of these movements in the months of June and July, in the department of Western Virginia, Washington, Susquehannah, and the Middle Department, much confusion arose from the rebel forces invading so many points where they were brought in conflict alternately with different, and independent Federal commanders, who all received their instructions and reported to the General-in-chief, or through General Halleck at Washington. From the time of the first raid the telegraph wires were frequently down between Washington and City Point, making it necessary to transmit messages a part of the way by boat. It took from twenty-four to thirty-six hours to get dispatches through and return answers back; so that often orders would be given, and then information would be received showing a different state of facts from those on which they were based, causing a confusion and apparent contradiction of orders that must have considerably embarrassed those who had to execute them, and rendered operations against the enemy less effective than they otherwise would have been. To remedy this evil, it was recommended by General Grant that one general should be appointed to have supreme command of all the forces actively engaged in the field in those departments. On the 2d of August, General Grant ordered General Sheridan to report in person to Major-General Halleck, chief-of-staff, at Washington, with a view to his assignment to the command of all the forces against Early.

At this time the enemy was concentrated in the neighborhood of Winchester. General Hunter’s forces at that time were posted on the Monocacy, at the crossing of the Baltimore and Ohio railroad. Before any definite orders were given in relation to army movements, General Grant paid a visit to General Hunter at his headquarters, and gave definite written instructions for the coming campaign. General Hunter having expressed a willingness to be relieved of command, General Sheridan was telegraphed to join General Grant at Monocacy.

On the 7th of August the middle department and the departments of West Virginia, Washington, and Susquehanna were constituted into the “Middle military division,” and Major-General Sheridan was assigned to command of the same.

Two divisions of cavalry, commanded by Generals Torbert and Wilson, were sent to Sheridan from the Army of the Potomac. The first reached him at Harper’s Ferry about the 11th of August.

General Sheridan was confronted by a rebel force of about twenty thousand men. Although a much larger force than this was at his disposal, yet the numerous points that lay exposed to the incursions of the enemy prevented the Federal commander from concentrating his army for offensive operations, and the movements of the campaign for the first month were of a desultory character.

On the 11th of August a detachment of Federal cavalry encountered the enemy a few miles beyond Winchester, and engaged him for two hours, with a loss to the Unionists of thirty men. Some infantry supports coming up, the contest was continued from eleven o’clock till two, when the rebels were driven from their position, but not until they had inflicted severe loss on the Federals. The enemy were followed the next day to Cedar creek, a few miles from Strasburg, where, from a strong position, they resisted the Union advance throughout the day, but retreated at nightfall, when the Federals pursued, and entered Strasburg.

On the 15th, Colonel Mosby, the noted rebel guerrilla, made a foray through Snicker’s Gap, and succeeded in capturing a Federal supply train, which he carried off in safety, securing seventy-five wagons, two hundred prisoners, six hundred horses, and two hundred beeves.

Not knowing the extent or character of the rebel forces in their rear, the Federals became alarmed, and beat a hasty retreat to Winchester, destroying many of their stores, which they were unable to remove in their flight. Being closely followed by the rebels, the Unionists continued their retreat to Harper’s Ferry, fearful that Longstreet’s army had reinforced Early.

On the 21st of August, General Sheridan had posted his army on an important eminence called Summit Point, two miles out from Charlestown, where he was attacked by General Early on that day, the fight lasting from ten o’clock till dark, when the Federals were defeated, losing three hundred men. They were compelled to retreat to Bolivar Heights.

During all this time, General Sheridan was restrained from inaugurating any decisive movement against the enemy, owing to the important points which it was necessary for him to cover, and which would be jeopardized, should any serious misfortune befall his army. At a conference held on the 15th of September, at Charleston, between Generals Grant and Sheridan, it was determined that an immediate advance should be made on the enemy. General Sheridan, always noted for the celerity of his movements, took the field in less time than General Grant thought it possible for him to be in readiness, and at 3 o’clock on Monday, the 18th, the troops marched to meet the foe.