The weak point of McClellan’s strategy was making itself felt.  In advancing on Richmond by way of the Peninsula he had deliberately adopted what are called in strategy “the exterior lines.”  That is, his forces were distributed on the arc of a circle, of which Richmond and the Confederate army were the centre.  If, landing on the Peninsula, he had been able to advance at once upon Richmond, the enemy must have concentrated for the defence of his capital, and neither Banks nor Washington would have been disturbed.  But the moment his advance was checked, as it was at Yorktown, the enemy could detach at his leisure in any direction that he pleased, and McClellan was absolutely unable to support the threatened point.  The strategy of exterior lines demands, for success, a strong and continuous pressure on the enemy’s main army, depriving him of the time and the space necessary for counterstroke.  If this is impossible, a skilful foe will at once make use of his central position.

Lincoln appears to have had an instinctive apprehension that McClellan might not be able to exert sufficient pressure to hold Johnston fast, and it was for this reason that he had fought so strongly against the Peninsula line of invasion.  It was the probability that the Confederates would use their opportunity with which Stanton had now to deal, complicated by the fact that their numbers were believed to be much greater than they really were.  Still the problem was not one of insurmountable difficulty.  Banks and Fremont united had 40,000 men, McDowell over 30,000.  A few marches would have brought these forces into combination.  Banks and Fremont, occupying Staunton, and moving on Gordonsville, would have soon taken up communication with McDowell; an army 70,000 strong, far larger than any force the Confederates could detach against it, would have threatened Richmond from the north and west, and, at the same time, would have covered Washington.  This plan, though not without elements of danger, offered some advantages.  Nor were soldiers wanting to advise it.  Both Rosecrans and Shields had submitted schemes for such a combination.  Mr. Stanton, however, preferred to control the chessboard by the light of unaided wisdom; and while McDowell was unnecessarily strengthened, both Banks and Fremont were dangerously weakened.

The only single point where the Secretary showed the slightest sagacity was in apprehending that the Confederates would make use of their opportunity, and overwhelm one of the detachments he had so ingeniously isolated.

On April 29 Johnston proposed to Davis that his army should be withdrawn from the Peninsula, and that the North should be invaded by way of the Valley.* (* O.R. volume 11 part 3 page 477.) Lee, in the name of the President, replied that some such scheme had been for some time under consideration; and the burden of his letters, as we have seen, both to Ewell and Jackson, was that a sudden and heavy blow should be struck at some exposed portion of the invading armies.  Mr. Stanton was so far right; but where the blow was to be struck he was absolutely unable to divine.