A very considerable force, under command of Major-General Sigel, was so held for the protection of West Virginia, and the frontiers of Maryland and Pennsylvania. Whilst these troops could not be withdrawn to distant fields without exposing the North to invasion by comparatively small bodies of the enemy, they could act directly to their front, and give better protection than if lying idle in garrison. By such a movement they would either compel the enemy to detach largely for the protection of his supplies and lines of communication, or he would lose them. General Sigel was therefore directed to organize all his available force into two expeditions, to move from Beverly and Charleston, under command of Generals Ord and Crook, against the East Tennessee and Virginia Railroad.
Subsequently, General Ord having been relieved at his own request, General Sigel was instructed at his own suggestion, to give up the expedition by Beverly, and to form two columns, one under General Crook, on the Kanawha, numbering about ten thousand men, and one on the Shenandoah, numbering about seven thousand men. The one on the Shenandoah to assemble between Cumberland and the Shenandoah, and the infantry and artillery advanced to Cedar Creek with such cavalry as could be made available at the moment, to threaten the enemy in the Shenandoah Valley, and advance as far as possible; while General Crook would take possession of Lewisburg with part of his force and move down the Tennessee Railroad, doing as much damage as he could, destroying the New River Bridge and the salt-works, at Saltville, Va.
Owing to the weather and bad condition of the roads, operations were delayed until the 1st of May, when, everything being in readiness and the roads favorable, orders were given for a general movement of all the armies not later than the 4th of May.
My first object being to break the military power of the rebellion, and capture the enemy's important strongholds, made me desirous that General Butler should succeed in his movement against Richmond, as that would tend more than anything else, unless it were the capture of Lee's army, to accomplish this desired result in the East. If he failed, it was my determination, by hard fighting, either to compel Lee to retreat, or to so cripple him that he could not detach a large force to go north, and still retain enough for the defence of Richmond. It was well understood, by both Generals Butler and Meade, before starting en the campaign, that it was my intention to put both their armies south of the James River, in case of failure to destroy Lee without it.
Before giving General Butler his instructions, I visited him at Fort Monroe, and in conversation pointed out the apparent importance of getting possession of Petersburg, and destroying railroad communication as far south as possible. Believing, however, in the practicability of capturing Richmond unless it was reinforced, I made that the objective point of his operations. As the Army of the Potomac was to move simultaneously with him, Lee could not detach from his army with safety, and the enemy did not have troops elsewhere to bring to the defence of the city in time to meet a rapid movement from the north of James River.
I may here state that, commanding all the armies as I did, I tried, as far as possible, to leave General Meade in independent command of the Army of the Potomac. My instructions for that army were all through him, and were general in their nature, leaving all the details and the execution to him. The campaigns that followed proved him to be the right man in the right place. His commanding always in the presence of an officer superior to him in rank, has drawn from him much of that public attention that his zeal and ability entitle him to, and which he would otherwise have received.
The movement of the Army of the Potomac commenced early on the morning of the 4th of May, under the immediate direction and orders of Major-General Meade, pursuant to instructions. Before night, the whole army was across the Rapidan (the fifth and sixth corps crossing at Germania Ford, and the second corps at Ely's Ford, the cavalry, under Major-General Sheridan, moving in advance,) with the greater part of its trains, numbering about four thousand wagons, meeting with but slight opposition. The average distance travelled by the troops that day was about twelve miles. This I regarded as a great success, and it removed from my mind the most serious apprehensions I had entertained, that of crossing the river in the face of an active, large, well-appointed, and ably commanded army, and how so large a train was to be carried through a hostile country, and protected. Early on the 5th, the advance corps (the fifth, Major-General G. K. Warren commanding) met and engaged the enemy outside his intrenchments near Mine Run. The battle raged furiously all day, the whole army being brought into the fight as fast as the corps could be got upon the field, which, considering the density of the forest and narrowness of the roads, was done with commendable promptness.
General Burnside, with the ninth corps, was, at the time the Army of the Potomac moved, left with the bulk of his corps at the crossing of the Rappahannock River and Alexandria Railroad, holding the road back to Bull Run, with instructions not to move until he received notice that a crossing of the Rapidan was secured, but to move promptly as soon as such notice was received. This crossing he was apprised of on the afternoon of the 4th. By six o'clock of the morning of the 6th he was leading his corps into action near the Wilderness Tavern, some of his troops having marched a distance of over thirty miles, crossing both the Rappahannock and Rapidan rivers. Considering that a large proportion, probably two-thirds of his command, was composed of new troops, unaccustomed to marches, and carrying the accoutrements of a soldier, this was a remarkable march.