Among Spies.
Moreover, instead of being among a population eager to give him every scrap of information, Lee was now among one where every man, woman, and child was a spy on his own movements. In the absence, then, of definite knowledge touching the Union army, he decided to march on Harrisburg with his whole force, and issued orders accordingly.
Union Army crosses the Potomac.
When there was no longer a shadow of doubt that Lee's whole army was on the march up the Cumberland Valley, sweeping that valley clean as it went, the Union army also crossed the Potomac, on the 25th and 26th of June, and at once began moving up east of South Mountain, so as to discharge the double duty laid upon it all along of keeping between the enemy and Washington, while at the same time feeling for him through the gaps of South Mountain as it marched. For this task the Union general kept his cavalry well in hand, instead of letting it roam about at will in quest of adventures.
Hooker's Plan.
This order of march threw the left wing out as far as Boonsborough and Middletown, with Buford's cavalry division watching the passes by which the enemy would have to defile, should he think of making an attack from that flank.[21] The rest of the army was halted, for the moment, around Frederick. The plan of operations, as first fixed, did not lack in boldness or originality. It was to follow Lee up the Cumberland Valley with two corps, numbering twenty thousand men, while the rest of the army should continue its march toward the enemy on the east side of South Mountain, but within supporting distance. As this would be doing just what Lee[22] had most reason to dread, it would seem most in accordance with the rules of war. At any rate, it initiated a vigorously aggressive campaign.
At this critical moment the Union army was, most unexpectedly, deprived of its head.
Hooker is thwarted.
In its pursuit of Lee this army had been much hampered by divided counsels, when, if ever united counsels were imperatively called for, now was the time. Worse still, it had too many commanders, both civil and military. The President, the Cabinet, the General-in-Chief (Halleck), and even some others, in addition to the actual commander, not to speak of the newspapers, had all taken turns in advising or suggesting what should, or what should not, be done. United action, sincere and generous co-operation, as between government and army, were therefore unattainable here. The government did not trust its general: the general respected the generalship of the Cabinet most when it was silent. Nobody in authority seemed willing to grant Hooker what he asked for, let it be ever so reasonable, or permit him to carry out his own plans unobstructed, were they ever so promising or brilliant. He could not get the fifteen or twenty thousand soldiers who were then dawdling about the camps at Baltimore, Washington, and Alexandria. He was brusquely snubbed when he asked for leave to break up the post at Harper's Ferry, when by doing so ten thousand good troops would have been freed to act against the enemy's line of retreat.
Harmony being impossible, Lee seemed likely to triumph through the dissensions of his enemies.