"This question is the extent to which the line of the Potomac should be guarded, after the army leaves, in order to cover Maryland and Pennsylvania from invasion by large or small parties of the enemy.

"It will always be somewhat difficult to guard the immediate line of the river, owing to its great extent and the numerous passages which exist.

66

It has long appeared to me that the best way of covering this line would be by occupying Front Royal, Strasburg, Wardensville and Moorefield, or the debouches of the several valleys in which they are situated.

"These points, or suitable places in their vicinity, should be strongly intrenched and permanently held. One great advantage of this arrangement would be the covering the Baltimore and Ohio railroad, and an essential part of the system would be the construction of the link of railway from Winchester to Strasburg, and the rebuilding of the Manassas Gap railway bridge over the Shenandoah.

66

The intrenchment of Manassas Junction would complete the system for the defence of the approaches to Washington and the upper Potomac. Many months ago I recommended this arrangement; in fact, gave orders for it to be carried into effect. I still regard it as essential under all circumstances.

"The views of the chief engineer of this army, in regard to the defences and garrison of Harper's Ferry and its defences, are in your possession.

"The only troops under my command, outside of the organization of the army of the Potomac, are the Maryland brigade, under General Kenley; the 54th Pennsylvania, Colonel Voss; 12th Illinois cavalry, and Colonel Davis's 8th New York cavalry; total, 2,894 infantry, one battery, and about 900 cavalry men.

"There are also two of my regiments of cavalry (about 750 men,) guarding the Baltimore and Ohio railroad between Hancock and Cumberland.

"As I have no department, and command simply an active army in the field, my responsibility for the safety of the line of the Potomac and the States north of it must terminate the moment I advance so far beyond that line as to adopt another for my base of operations. The question for the general-inchief to decide, and which I regard as beyond my province, is this:

"1st. Shall the safety of Harper's Ferry and the line of the Potomac be regarded as assured by the advance of the army south of the Blue Ridge, and the line left to take care of itself?

"2d. If it is deemed necessary to hold the line, or that hereinbefore indicated in advance of it, how many troops shall be placed there, at what points, (and in what numbers and of what composition at each,) and where shall they be supplied-i. l., from the army, or from other sources?

66

Omitting the detached troops mentioned above, and the small garrisons of Boonsboro' and Frederick, the last returns show the strength of this army for duty to be about (116,000) one hundred and sixteen thousand officers and men. This includes the divisions of Stoneman and Whipple, but does not include Heintzelman, Sigel, and Bayard.

"If Harper's Ferry and the river above are rendered fully secure, it is possible that the active army, if it supplies the garrison, may be reduced so much as to be inadequate to the purposes contemplated. If it is preserved intact, Maryland, Pennsylvania, and the Baltimore and Ohio railroad may be unduly exposed.

I leave the decision of these grave questions to the general-in-chief. I know nothing of the number of troops at Baltimore, &c.

"An important element in the solution of this problem is the fact that a great portion of Bragg's army is probably now at liberty to unite itself with Lee's command.

"I commence crossing the river at Berlin in the morning, and must ask a prompt decision of the questions proposed herein.

"Major General HALLECK,

"General-in-Chief, Washington.

"GEORGE B. MCCLELLAN,

To which I received the following reply:

"WASHINGTON, October 26, 1862-1.35 P. m. "In addition to the command which you had when I came here, you also have the greater part of that of Major General Pope. Moreover, you have been authorized to use any troops within your reach in General Wool's department, and in Western Virginia. General Banks's command is also under your direction, with the single restriction that he is not to remove troops from Washington till he has notified me of his orders.

The

"Since you left Washington I have advised and suggested in relation to your movements, but I have given you no orders; I do not give you any now. government has intrusted you with defeating and driving back the rebel army in your front. I shall not attempt to control you in the measures you may adopt for that purpose. You are informed of my views, but the President has left you at liberty to adopt them or not, as you may deem best.

66

You will also exercise your own discretion in regard to what points on the Potomac and the Baltimore and Ohio railroad are to be occupied or fortified. I will only add that there is no appropriation for permanent intrenchments on that line. Moreover, I think it will be time enough to decide upon fortifying Front Royal, Strasburg, Wardensville, and Moorefield, when the enemy is driven south of them, and they come into our possession.

"I do not think that we need have any immediate fear of Bragg's army. You are within (20) twenty miles of Lee's, while Bragg is distant about (400) four hundred miles.

"Major General G. B. MCCLELLAN."

On the 29th I sent the following:

"H. W. HALLECK,
"General-in-Chief.

"HEADQUARTERS ARMY OF THE POTOMAC,
"October 29, 1862–1.15 p. m.

“On the 25th instant I sent you a despatch requesting you to decide what steps should be taken to guard the line of the Potomac when this army leaves here. To this I received your reply that I had been intrusted by the President with defeating and driving away the rebel army; that you had given me no orders heretofore-did not give me any then, &c. Under these circumstances, I have only to make such arrangements for guarding this extended line as the means at my disposal will permit, at the same time keeping in view the supreme necessity of maintaining the moving army in adequate force to meet the rebel army before us.

"The dispositions I have ordered are as follows, viz: Ten thousand men to be left at Harper's Ferry; one brigade of infantry in front of Sharpsburg; Kenley's brigade of infantry at Williamsport; Kelly's brigade, including Colanel Campbell's 54th Pennsylvania infantry, at Cumberland; and between that point and Hancock. I have also left four small cavalry regiments to patrol and watch the river and the Baltimore and Ohio railroad from Cumberland down to Harper's Ferry.

'I do not regard this force as sufficient to cover securely this great extent of

line, but I do not feel justified in detaching any more troops from my moving columns; I would, therefore, recommend that some new regiments of infantry and cavalry be sent to strengthen the forces left by me.

"There should be a brigade of infantry and section of artillery in the vicinity of Cherry run, another brigade at Hancock, an additional brigade at Williamsport, one regiment at Hagerstown and one at Chambersburg, with a section of artillery at each place if possible. This is on the supposition that the enemy retain a considerable cavalry force west of the Blue Ridge; if they go east of it, the occupation of the points named in my despatch of the 25th instant will obviate the necessity of keeping many of these troops on the river.

"There are now several hundred of our wounded, including General Richardson, in the vicinity of Sharpsburg, that cannot possibly be moved at present. "I repeat, that I do not look upon the forces I have been able to leave from this army as sufficient to prevent cavalry raids into Maryland and Pennsylvania, as cavalry is the only description of troops adequate to this service, and I am, as you are aware, deficient in this arm.

"G. B. McCLELLAN, "Major General, Commanding.

To which I received on the 30th this reply:

"WASHINGTON, October 30, 1862-11.30 a. m. "Your telegram of yesterday was received late last evening. The troops proposed for Thoroughfare gap will be sent to that place whenever you are in position for their co-operation, as previously stated, but no new regiments can be sent from here to the upper Potomac. The guarding of that line is left to your own discretion with the troops now under your command.

“Major General G. B. MCCLELLAN.”

"H. W. HALLECK,
"General-in-Chief.

I accordingly left the 12th corps at Harper's Ferry, detaching one brigade to the vicinity of Sharpsburg. General Morell was placed in command of the line from the mouth of the Antietam to Cumberland; General Slocum in command of Harper's Ferry and the line east of the mouth of the Antietam.

The orders given to these officers were as follows:

“HEADQUARTERS ARMY OF the Potomac,
"October 29, 1862-1 p. m

"The general commanding directs that you send one brigade of your corps to march at once to the position now occupied by General F. J. Porter's corps, in front of Sharpsburg, to watch and guard the line of the river, the ford near the mouth of the Antietam creek to the mouth of the Opequan creek.

"The officer in command will also take steps to afford proper protection to the sick and wounded in the hospitals in the vicinity of Sharpsburg and Boonsboro'. The regiment now at Boonsboro' will be placed under his orders. General Kenley, at Williamsport, will guard the river from the mouth of the Opequan alone, including the ford at the mouth of the Opequan.

"The commanding general also directs that you take immediate steps to establish the remainder of your corps as follows, viz: one brigade on Maryland heights, one brigade on Loudon heights, with the remainder on Bolivar heights and at Harper's Ferry.

"These dispositions should be made at once, so that General Couch can move with his corps. Please acknowledge the receipt of this.

46 General H. W. SLOCUM,

"R. B. MARCY,

"Commanding Army Corps, Harper's Ferry."

"HEADQUARTERS ARMY OF THE POTOMAC,
"October 31, 1862.

"GENERAL: I am instructed by the commanding general to say to you, that he has selected you to perform the highly important and responsible duty of taking charge of and commanding the troops left for the defence of the line of the Potomac river, from the mouth of the Antietam to Cumberland, as well as any other troops that may hereafter be sent for the protection of the Maryland and Pennsylvania frontier within the limits of the lines herein specified. The force which has been left to guard the line is not deemed adequate to prevent cavalry raids, but it is all that the commanding general feels authorized to detach from the army of the Potomac at the present time, and it devolves upon you to make the best use of this force in your power. You will have four cavalry regiments under your command, which should be so distributed along the river as to watch all the available fords, and give timely notice to the infantry of the approach of any force of rebels.

66

You will afford all the protection in your power to the Baltimore and Ohio railroad.

"You will endeavor to prevent any cavalry raids into Maryland and Pennsylvania.

"You will take steps to have all the sick and wounded of our army, as well as of the rebel army within your lines, properly taken care of until they can be sent to general hospitals, or discharged, or paroled.

"You will make your headquarters at Hagerstown, and occasionally visit the different parts of your line.

You will please report promptly to these headquarters everything of importance that occurs within the limits of your command.

"The three brigades now at Cumberland, Williamsport, and Sharpsburg, including the fifty-fourth Pennsylvania volunteers, near Cumberland, will be under your command. They are commanded by Generals Kelly, Kenley, and Gordon. "Very respectfully, your obedient servant,

"General G. W. MORELL,

"Commanding Upper Potomac."

"S. WILLIAMS, "Assistant Adjutant General.

On the 25th of October the pontoon bridge at Berlin was constructed, there being already one across the Potomac, and another across the Shenandoah, at Harper's Ferry.

On the 26th two divisions of the ninth corps, and Pleasonton's brigade of cavalry, crossed at Berlin and occupied Lovettsville.

The first, sixth, and ninth corps, the cavalry, and the reserve artillery, crossed at Berlin between the 26th of October and the 2d of November.

The second and fifth corps crossed at Harper's Ferry between the 29th of October and the 1st of November. Heavy rains delayed the movement considerably in the beginning, and the first, fifth and sixth corps were obliged to halt at least one day at the crossings to complete, as far as possible, necessary supplies that could not be procured at an earlier period.

The plan of campaign I adopted during this advance was to move the army, well in hand, parallel to the Blue Ridge, taking Warrenton as the point of direc

tion for the main army; seizing each pass on the Blue Ridge by detachments, as we approached it, and guarding them after we had passed as long as they would enable the enemy to trouble our communications with the Potomac. It was expected that we would unite with the eleventh corps and Sickles's division near Thoroughfare gap. We depended upon Harper's Ferry and Berlin for supplies until the Manassas Gap railway was reached; when that occurred the passes in our rear were to be abandoned, and the army massed ready for action or movement in any direction.

It was my intention if, upon reaching Ashby's or any other pass, I found that the enemy were in force between it and the Potomac in the valley of the Shenandoah, to move into the valley and endeavor to gain their rear.

I hardly hoped to accomplish this, but did expect that by striking in between Culpeper Court House and Little Washington I could either separate their army and beat them in detail, or else force them to concentrate as far back as Gordonsville, and thus place the army of the Potomac in position either to adopt the Fredericksburg line of advance upon Richmond, or to be removed to the Peninsula, if, as I apprehended, it were found impossible to supply it by the Orange and Alexandria railroad beyond Culpeper.

On the 27th of October the remaining divisions of the ninth corps crossed at Berlin, and Pleasonton's cavalry advanced to Purcellville. The concentration of the sixth corps, delayed somewhat by intelligence as to the movements of the enemy near Hedgesville, &c., was commenced on this day, and the first corps was already in motion for Berlin.

On the 28th the first corps and the general headquarters reached Berlin. On the 29th the reserve artillery crossed and encamped near Lovettsville. Stoneman's division, temporarily attached to the ninth corps, occupied Leesburg; Averill's cavalry brigade moved towards Berlin from Hagerstown; two divisions of the ninth corps moved to Wheatland, and one to Waterford. The second corps commenced the passage of the Shenandoah at Harper's Ferry, and moved into the valley east of Loudon heights.

On the 30th the first corps crossed at Berlin and encamped near Lovettsville, and the second corps completed the passage of the Shenandoah. The fifth corps commenced its march from Sharpsburg to Harper's Ferry.

On the 31st the second corps moved to the vicinity of Hillsborough; the sixth corps reached Boonsboro'; the fifth corps reached Harper's Ferry, one division crossing the Shenandoah.

On the 1st of November the first corps moved to Purcellville and Hamilton; the second corps to Woodgrove; the fifth corps to Hillsborough; the sixth corps reached Berlin, one division crossing. Pleasonton's cavalry occupied Philomont, having a sharp skirmish there and at Bloomfield.

On November 2 the second corps occupied Snicker's gap; the fifth corps, Snickersville; the sixth corps crossed the Potomac and encamped near Wheatland; the ninth corps advanced to Bloomfield, Union, and Philomont. Pleasonton drove the enemy out of Union. Averill was ordered to join Pleasonton. The enemy offered no serious resistance to the occupation of Snicker's gap, but advanced to gain possession of it with a column of some 5,000 to 6,000 infantry, who were driven back by a few rounds from our rifled guns.

On the 3d the first corps moved to Philomont, Union, Bloomfield, &c.; the second corps to the vicinity of Upperville; the fifth corps remained at Snicker's gap; the sixth corps moved to Purcellville; the ninth corps moved towards Upperville. Pleasonton drove the enemy out of Upperville after a severe fight. On the 4th the 2d corps took possession of Ashby's gap; the 6th corps reached Union; the 9th corps, Upperville; the cavalry occupied Piedmont. On the 5th the 1st corps moved to Rectortown and White Plains; one division of the 2d corps to the intersection of the Paris and Piedmont with the Upperville and Barber's road; the 6th corps to the Aldie pike, east of Upperville;