So vast is the amount of stores necessary for the subsistence, health, and armament of a host like McClellan’s that a change of base is an operation which can only be effected under the most favourable circumstances.* (* The Army of the Potomac numbered 105,000 men, and 25,000 animals. 600 tons of ammunition, food, forage, medical and other supplies had to be forwarded each day from White House to the front; and at one time during the operations from fifty to sixty days’ rations for the entire army, amounting probably to 25,000 tons, were accumulated at the depot. 5 tons daily per 1000 men is a fair estimate for an army operating in a barren country.) It is evident, then, that the possibility of the enemy shifting his line of operations to the James, abandoning the York River Railroad, might easily have escaped the penetration of either Lee or Jackson.  They were not behind the scenes of the Federal administrative system.  They were not aware of the money, labour, and ingenuity which had been lavished on the business of supply.  They had not seen with their own eyes the fleet of four hundred transports which covered the reaches of the York.  They had not yet realised the enormous advantage which an army derives from the command of the sea.

Nor were they enlightened by the calmness with which their immediate adversaries on the field of battle regarded Jackson’s possession of Old Cold Harbour.  Still, one fact was manifest:  the Federals showed no disposition whatever to weaken or change their position, and it was clear that the success was not to be attained by mere manoeuvre.  Lee, seeing Hill’s division roughly handled, ordered Longstreet forward, while Jackson, judging from the sound and direction of the firing that the original plan had failed, struck in with vigour.  Opposed to him was Sykes’ division of regulars, supported by eighteen guns, afterwards increased to twenty-four; and in the men of the United States Army the Valley soldiers met a stubborn foe.  The position, moreover, occupied by Sykes possessed every advantage which a defender could desire.  Manned even by troops of inferior mettle it might well have proved impregnable.  The valley was wider than further west, and a thousand yards intervened between the opposing ridges.  From either crest the cornfields sloped gently to the marshy sources of the creek, hidden by tall timber and dense undergrowth.  The right and rear of the position were protected by a second stream, running south to the Chickahominy, and winding through a swamp which Stuart, posted on Jackson’s left, pronounced impassable for horsemen.  Between the head waters of these two streams rose the spur on which stands McGehee’s house, facing the road from Old Cold Harbour, and completely commanding the country to the north and north-east.  The flank, therefore, was well secured; the front was strong, with a wide field of fire; the Confederate artillery, even if it could make its way through the thick woods on the