Lee, as usual, had divined the political forces working on the Union armies from Washington and had maneuvered with a combination of skill and daring that exactly met the situation. Throwing his left forward (under Ewell) in the Shenandoah Valley he had driven Milroy out of Winchester on the fourteenth of June and next day secured a foothold across the Potomac. Then the rest of his army followed. It was so much stretched out (to facilitate its food supply) that Lincoln again wished to strike it at any vulnerable spot. But the Cabinet in general (and Stanton in particular) were still determined that the Union army should be their passive shield, not their active sword. On the twenty-fourth Ewell was already beginning to semicircle Gettysburg from the Cumberland Valley. On the twenty-eighth, the day on which Meade succeeded Hooker in the Federal command, the Confederate semicircle, now formed by Lee's whole army, stretched from Chambersburg on the west, through Carlisle on the north, to York on the east; while the massed Federals were still in Maryland, near Middletown and Frederick, thirty miles south of Gettysburg, and only forty miles northwest of nervous Washington. Hooker's successor, George G. Meade, was the fifth defender of Washington within the last ten months. Luckily for the Union, Meade was a sound, though not a great, commander, and his hands were fairly free. Luckily again, he was succeeded in command of the Fifth Corps by George Sykes, the excellent leader of those magnificent regulars who fought so well at Antietam and Second Manassas. The change from interference to control was made only just in time at Washington; for three days after Meade's free hand began to feel its way along the threatened front the armies met upon the unexpected battlefield of Gettysburg.