McClellan, again reinforced, still professed his readiness to take Richmond under conditions that suited himself. But the most promising Northern force now seemed to be Pope's Army of Virginia, coming down from the line of the Potomac, forty-seven thousand strong, composed of excellent material, and heralded by proclamations which even McClellan could never excel. John Pope, Halleck's hero of Island Number Ten, came from the West to show the East how to fight. "I presume that I have been called here to lead you against the enemy, and that speedily. I hear constantly of taking strong positions and holding them--of lines of retreat and bases of supplies. Let us discard such ideas. Let us study the probable line of retreat of our opponents, and leave our own to take care of themselves." His Army of Virginia contained Frémont's (now Sigel's) corps, as well as those of Banks and McDowell--all experts in the art of "chasing Jackson." Jackson was soon ready to be chased again. The Confederate strength had been reduced by the Seven Days and not made good by reinforcement; so Lee could spare Jackson only twenty-four thousand men with whom to meet the almost double numbers under Pope. But Jackson's men had the better morale, not only on account of their previous service but because of their rage to beat Pope, who, unlike other Northerners, was enforcing the harshest rules of war. His lieutenant, General von Steinwehr, went further, not only seizing prominent civilians as hostages (to be shot whenever he chose to draw his own distinctions between Confederate soldiers and guerillas) but giving his German subordinates a liberty that some of them knew well how to turn into license. This, of course, was most exceptional; for nearly all Northerners made war like gentlemen. Unhappily, those who did not were bad enough and numerous enough to infuriate the South. Halleck, who had now become chief military adviser to the Union Government, was as cautious as McClellan and had so little discernment that he thought Pope a better general than Grant. Lincoln, Stanton, and Halleck put their heads together; and an order soon followed which had the effect of relieving the pressure on Richmond and giving the initiative to Lee. Halleck ordered McClellan to withdraw from Harrison's Landing, take his Army of the Potomac round by sea to Aquia Creek, and join Pope on the Rappahannock--an operation requiring the whole month of August to complete.