The battle of Chancellorsville was fought, May 1 to 5, 1863, in the Wilderness country, south of the Rapidan, and resulted in the defeat of the Union Army and its falling back to its former position at Falmouth.
The defeats at Fredericksburg and Chancellorsville led to a general belief that another invasion of the North would be made by Lee's army. Such an invasion involved Milroy's command at Winchester, then in the Middle Department, commanded by Major-General Robert C. Schenck, whose headquarters were at Baltimore.
This much in retrospect seems necessary to give a better understanding of the events soon to be mentioned.
Soon after Chancellorsville, the Confederate forces in the upper Shenandoah Valley became more active, and frequent indecisive conflicts between them and our scouting parties took place. Our regular scouts, who generally travelled by night in Confederate dress, brought in rumors almost every day of an intended attack on Winchester by troops from Lee's army. In May I was given special charge of these scouts. So uniform were their reports as to the proposed attacks that I gave credence to them, and advised Milroy that unless he was soon to be largely reinforced it would be well to retire from his exposed position. He refused to believe that anything more than a cavalry raid into the Valley or against him would be made, and he felt strong enough to defeat it. He argued that Lee would not dare to detach any part of his infantry force from the front of the Army of the Potomac. But in addition to the reports referred to, I learned as early as the 1st of June, through correspondence secretly brought within our lines from an officer of Lee's army to which I gained access, that Lee contemplated a grand movement North, and that his army would reach Winchester on June 10, 1863. The Secessionists of Winchester generally believed we would be attacked on that day. I gave this information to Milroy, but he still persisted in believing the whole story was gotten up to cause him to disgracefully abandon the Valley.( 4)
The 10th of June came, and the Confederate Army failed to appear. This confirmed Milroy in his disbelief in a contemplated attack with a strong force, and my credulity was ridiculed. As early, however, as June 8th, Milroy wired Schenck at Baltimore that he had information that Lee had mounted an infantry division to join Stuart's cavalry at Culpeper; that the cavalry force there was "probably more than twice 12,000," and that there was "doubtless a mighty raid on foot."( 5) Colonel Don Piatt, Schenck's chief of staff, visited and inspected the post at Winchester on the 10th and 11th, and when he reached Martinsburg, Va., on his return on the 11th, he dispatched Milroy to immediately take steps to remove his command to Harper's Ferry, leaving at Winchester only a lookout which could readily fall back to Harper's Ferry.( 6) This order was sent in the light of what Piatt deemed the proper construction of a dispatch of that date from Halleck to Schenck, and from the latter to him. Milroy at once wired Schenck of the receipt of the Piatt dispatch, saying:
"I have sufficient force to hold the place safely, but if any force is withdrawn the balance will be captured in twenty-four hours. All should go, or none."
This brought, June 12th, a dispatch from Schenck to Milroy in this language:
"Lt.-Col. Piatt has . . . misunderstood me, and somewhat exceeded his instructions. You will make all the required preparations for withdrawing, but will hold your position in the meantime."
On the 12th Milroy reported skirmishes with Confederate cavalry on the Front Royal and Strasburg roads, adding:
"I am perfectly certain of my ability to hold this place. Nothing but cavalry appears yet. Let them come."