Even before Stuart definitely reported this fact, Johnston had so far penetrated Patterson's purpose that he began his own movement toward Manassas, sending first the heavier and more slowly moving corps across the mountains to a point where railroad transportation was to meet them, and thus clearing the way for the cavalry and the lighter infantry and the well-horsed field batteries to proceed over country roads without the assistance of railroad cars.
Thus the "pepper box" system of strategy which prevailed at Washington met its first defeat. If Patterson had been sent at the outset to strengthen McDowell the result of the battle of Manassas might or might not have been different from what it was. But at any rate that arrangement would have given to McDowell a much greater preponderance of strength than he actually had on that battlefield. If Patterson had not gone to the valley of course Johnston would not have gone thither to meet him, and the bulk of Johnston's force would have been added to Beauregard's. But Patterson's army very largely outnumbered the force that Johnston had at Winchester within striking distance of Manassas, so that the total result of the plan of concentration would have been to strengthen McDowell.
More important still is the fact that while Johnston actually got a large part of his army to Manassas in time to decide the battle, Patterson never got there at all. So in considering the policy that sent Patterson to the valley instead of sending him to the line of Bull Run, we are entitled to reckon it as the cause of Patterson's complete absence from a field on which his valley adversary was present with timely and sorely needed strength.
In the meantime and throughout the summer there was a civil war going on in Missouri with varying fortunes. It occupied many thousands of men who might perhaps have been more wisely and effectively employed in aid of the one great movement upon Richmond, which if it had been thus made conspicuously successful, would pretty certainly have made an end of the war before it had had time to develop its strength. Those operations in Missouri had a dramatic interest of their own. But they in no way bore upon the problems of grand strategy which were meanwhile the proper and legitimate objects of supreme concern and consideration by the two stalwart contestants.