When intelligence now reached Washington that the head of Lee’s column was approaching the Upper Potomac, while the rear was south of the Rappahannock, the President wrote to General Hooker:  “If the head of Lee’s army is at Martinsburg, and the tail of it on the plank road between Fredericksburg and Chancellorsville, the animal must be very slim somewhere—­could you not break him?”

General Hooker did not seem to be able to determine upon a decisive course of action, in spite of the tempting opening presented to him by Lee.  It would seem that nothing could have been plainer than the good policy of an attack upon Hill at Fredericksburg, which would certainly have checked Lee’s movement by recalling Longstreet from Culpepper, and Ewell from the Valley.  But this bold operation did not appear to commend itself to the Federal authorities.  Instead of reenforcing the corps sent across at Fredericksburg and attacking Hill, General Hooker withdrew the corps, on the 13th, to the north bank of the river, got his forces together, and began to fall back toward Manassas, and even remained in ignorance, it seems, of all connected with his adversary’s movements.  Even as late as the 17th of June, his chief-of-staff, General Butterfield, wrote to one of his officers; “Try and hunt up somebody from Pennsylvania who knows something, and has a cool enough head to judge what is the actual state of affairs there with regard to the enemy. My impression is, that Lee’s movement on the Upper Potomac is a cover for a cavalry-raid on the south side of the river....  We cannot go boggling around until we know what we are going after.”

Such was the first result of Lee’s daring movement to transfer military operations to the region north of the Potomac.  A Northern historian has discerned in his plan of campaign an amount of boldness which “seemed to imply a great contempt for his opponent.”  This is perhaps a somewhat exaggerated statement of the case.  Without “boldness” a commander is but half a soldier, and it may be declared that a certain amount of that quality is absolutely essential to successful military operations.  But the question is, Did Lee expose himself, by these movements of his army, to probable disaster, if his adversary—­equal to the occasion—­struck at his flank?  A failure of the campaign of invasion would probably have resulted from such an attack either upon Hill at Fredericksburg, or upon Longstreet in Culpepper, inasmuch as Ewell’s column, in that event, must have fallen back.  But a defeat of the combined forces of Hill and Longstreet, who were within supporting distance of each other, was not an event which General Hooker could count upon with any degree of certainty.  The two corps numbered nearly fifty thousand men—­that is to say, two-thirds of the Southern army; General Hooker’s whole force was but about eighty thousand; and it was not probable that the eighty thousand would be able to rout the fifty thousand, when at Chancellorsville less than this last number of Southerners had defeated one hundred and twenty thousand.