possible delay in conforming to General Halleck's orders. I therefore sent to General Hooker the following letter:

HEADQUARTERS ARMY OF THE POTOMAC.

Berkeley, August 6, 1862-10 p.m.

MY DEAR GENERAL: I find it will not be possible to get the whole army int position before time to-morrow afternoon, which will be too late to support you and hold the entire position should the enemy attack in large force at daybreak, which there is strong reason to suppose he intends doing. Should we fight a general battle at Malvern it will be necessary to abandon the whole of our works here, and run the risk of getting back here. Under advices I have received from Washington, I think it necessary for you to abandon the position to-night, getting everything away before daylight. Please leave cavalry pickets at Malvern, with orders to destroy the Turkey Creek Bridge when they are forced back. The roads leading into Haxall's from the right should be strongly watched, and Haxall's at least held by strong cavalry force and some light batteries as long as possible. I leave the manner of the withdrawal entirely to your discretion. Please signal to the fleet when the withdrawal is about completed. Report frequently to these headquarters.

General Sumner was ordered up to support you, but will halt where this passes him, and will inform you where he is.

GEO. B. McCLELLAN,
Major-General.

General J. HOOKER, Commanding at Malvern Hill.

And the following reply was sent to General Halleck:

HEADQUARTERS ARMY OF THE POTOMAC.

Berkeley, August 6, 1862-11.30 p.m.

Dispatch of to-day received. I have not quite 4,000 cavalry for duty in cavalry division,so that I cannot possibly spare any more. I really need many more than I now have to carry out your instructions. The enemy are moving a large force on Malvern Hill. In view of your dispatches and the fact that I cannot place the whole army in position before daybreak, I have ordered Hooker to withdraw during the night if it is possible. If he cannot do so I must support him. Until this matter is developed I cannot send any batteries. I hope I can do so to-morrow if transportation is on hand. I will obey the order as soon as circumstances permit. My artillery is none too numerous now. I have only been able to send off some 1,200 sick. No transportation. There shall be no delay that I can avoid.

GEO. B. McCLELLAN.

Major-General, Commanding.

Major General H. W. HALLECK, Commanding U. S. Army.

Five batteries, with their horses and equipments complete, were embarked on the 7th and 8th, simultaneously with General Hooker's operations upon Malvern. I dispatched a cavalry force, under Colonel Averell, toward Savage Station to ascertain if the enemy were making any movements toward our right flank. He found a rebel cavalry regiment near White Oak Swamp Bridge and completely routed it, pursuing well toward Savage Station. These important preliminary operations assisted my preparations for the removal of the army to Aquia Creek, and the sending off our sick and supplies was pushed both day and night as rapidly as the means of transportation permitted.

On the subject of the withdrawal of the army from Harrison's Landing the following correspondence passed between the General-in-Chief and myself while the reconnaissances toward Richmond were in progress:

On the 2nd of August I received the following:

WASHINGTON, August 2, 1862-3.45 p.m.

You have not answered my telegram of July 30, 8 p.m. about the removal of your sick. Remove them as rapidly as possible and telegraph me when they will be out of your way. The President wishes an answer as early as possible.

H. W. HALLECK.

Major-General.

Major General GEORGE B. McCLELLAN.