Instead of specifically answering the President's concise interrogatories, McClellan, on the following day, presented to the Secretary of War a long letter, reciting in much detail his statement of what he had done since coming to Washington, and giving a rambling outline of what he thought might be accomplished in the future prosecution of the war. His reasoning in favor of an advance by Chesapeake Bay upon Richmond, instead of against Manassas Junction, rests principally upon the assumption that at Manassas the enemy is prepared to resist, while at Richmond there are no preparations; that to win Manassas would give us only the field of battle and the moral effect of a victory, while to win Richmond would give us the rebel capital with its communications and supplies; that at Manassas we would fight on a field chosen by the enemy, while at Richmond we would fight on one chosen by ourselves. If as a preliminary hypothesis these comparisons looked plausible, succeeding events quickly exposed their fallacy. The President, in his anxious studies and exhaustive discussion with military experts in the recent conferences, fully comprehended that under McClellan's labored strategical theories lay a fundamental error. It was not the capture of a place, but the destruction of the rebel armies that was needed to subdue the rebellion. But Mr. Lincoln also saw the fearful responsibility he would be taking upon himself if he forced McClellan to fight against his own judgment and protest, even though that judgment was incorrect. The whole subject, therefore, underwent a new and yet more elaborate investigation. The delay which this rendered necessary was soon greatly lengthened by two other causes. It was about this time that the telegraph brought news from the West of the surrender of Fort Henry, February 6, the investment of Fort Donelson on the thirteenth, and its surrender on the sixteenth, incidents which absorbed the constant attention of the President and the Secretary of War. Almost simultaneously, a heavy domestic sorrow fell upon Mr. Lincoln in the serious illness of his son Willie, an interesting and most promising lad of twelve, and his death in the White House on February 20. When February 22 came, while there was plainly no full compliance with the President's War Order No. I, there was, nevertheless, such promise of a beginning, even at Washington, as justified reasonable expectation. The authorities looked almost hourly for the announcement of two preliminary movements which had been preparing for many days: one, to attack rebel batteries on the Virginia shore of the Potomac; the other to throw bridges--one of pontoons, the second a permanent bridge of canal-boats--across the river at Harper's Ferry, and an advance by Banks's division on Winchester to protect the opening of the Baltimore and Ohio railroad and reestablish transportation to and from the West over that important route.