3,100 wagons, 17,000 horses, 8,000 mules, and 350 ambulances. I have no means of knowing the original number. The supply of clothing, camp and garrison equipage, &c., was good. In the river at the depot were bountiful supplies of forage, subsistence, and hospital stores.

The general commanding received orders early in August to evacuate the Peninsula. About the middle of the month one corps was thrown across the Chickahominy near its mouth, over a pontoon bridge of 2,000 feet in length; another command was ;pushed out toward New Kent Court-House over Bottom's Bridge; both with a view of protecting our trains, which were now sent forward rapidly in advance of the remainder of the army, by the pontoon bridge. They all passed in safety, and proceeded to the point of embarkation at Yorktown, Newport News, and Fortress Monroe. The transports were withdrawn under the direction of Colonel Sawtelle, who was my principal assistant at White House, and whose sagacity, zeal, promptness, and experience qualify him for any position in your Department. The headquarters left Harrison's Landing on the morning of the 16th of August, and the depot was broken up and abandoned, without loss, on the evening preceding. The march was a rapid and orderly one. I arrived at Fortress Monroe on the 18th by water from Yorktown. Fitz John Porter's corps, which was the first to cross the Chickahominy on the retreat, had already embarked for Aqua Creek to join Burnside and Pope. It was arranged that Heintzelman's corps should embark at Yorktown; Keye's should remain there; that Franklin should embark at Newport News, and Sumner at Fortress Monroe.

Leaving Colonel Sawtelle at the latter point to provide transports and push forward the troops, cavalry, horses, and artillery, I returned to Yorktown to hasten the embarkation of the Third Corps.

I finally left Fortress Monroe with General McClellan and staff on the 23rd of August, and arrived off Aqua early on the 24th instant, where we remained on the transports sixty hours awaiting orders. I left Aqua on the 26th instant, and arrived at Alexandria on the 27th, where headquarters went into camp near the city.

After the evacuation of Harrison's Landing the troops were pushed forward as rapidly as our means would permit. The officers and men seemed anxious and impatient to reach the scene of conflict in front of Washington, where it was known great battles must be fought, on which mighty national interests were staked.

I know the officers of our department used untiring exertions to expedite the embarkation; but it is now apparent that either we did not leave Harrison's Landing soon enough, or that General Pope did not fall back without risking a general engagement, as perhaps he might have done, at least earlier in the campaign, until more forces should arrive. I allude to the matter only in justice to our own department, which has sometimes peen accused of tardiness and having inadequate means of transportation on that occasion. Our means were ample and as great as the country could afford. Transports were assembled, as far as possible, from all available sources. It was not to be expected that there should be transports enough to move 100,000 men, with the artillery, cavalry, and trains, at once. It was necessary to perform this service by successive voyages of the vessels. It had required more than a month to transport the army from Alexandria to the Peninsula. It could not be brought back in a day. It did absorb three weeks' time to bring all back. Many of the wagon trains and a portion of the cavalry did not arrive until the army had left Washington on the Maryland campaign. Indeed, some did not join until after the battles of South Mountain and Antietam.