I take great pleasure in reporting that the conduct of the officers and men was most gallant.

Our casualties were 6 wounded.

Very respectfully, your obedient servant,

GARRETT DYCKMAN,

Colonel First Regiment New York Volunteers.

Brigadier-General BERRY,

Commanding Third Brigade, Third Division, Third Corps.

No. 78. Report of Brigadier General Erasmus D. Keyes,

U. S. Army, commanding Fourth Corps, of operations June 27-July 2.

HEADQUARTERS FOURTH CORPS, Harrison's Bar, July 20, 1862.

SIR: I have the honor to submit the following as my report of the operations of the Fourth Corps from June 27 to July 2 instant, embracing the time occupied by the flank movement or change of base of the Army of the Potomac from the Chickahominy to the James River:

At 1 o'clock a.m. June 28 I received orders to place three brigades of my corps and all their artillery and baggage across White Oak Swamp before daylight the same morning. My orders from General McClellan required that I should seize the strong positions on the opposite side, so as to cover most effectively the passage of the other troops. White Oak Swamp Bridge, had some time previously been destroyed by General Hooker, and other bridges were to be constructed for the passage of the whole army. Not a single bridge was ready for a wheeled carriage to cross until about two hours after sunrise. The moment the first was ready I pushed forward Brigadier-General Peck, commanding division, with Wessells' brigade in the advance, and immediately following General Peck, commanding division, with Wessells' brigade in the advance, and immediately following General Couch, commanding division, with Palmer's brigade.

Before 12 o'clock m. those two brigades, with several batteries of artillery, were established nearly 4 beyond the bridge, in position to guard the Charles City road, the New Market and Quaker roads, and the roads and paths below which lead to the James and Chickahominy Rivers. Before night Abercrombie's and Howe's brigades, of Couch's division, with most of the artillery and baggage of the Fourth Corps, had joined me. In this position, near the junction of many roads, I thought my corps could best cover the crossing of White Oak Swamp and thwart any designs the enemy might have to interrupt the passage of the army to the James River.

Naglee's brigade of Peck's division, and Miller's and Brady's batteries had been left behind to guard and destroy the railroad and Bottom's Bridges, which was done most effectively, and after several conflicts with the enemy they joined the balance of the Fourth Corps at Haxall's, on the James River, July 1. Colonel D. McM. Gregg, with a portion of his Eighth Pennsylvania Cavalry, was also detached and made a spirited reconnaissance on the east side of the Chickahominy, and rejoined the Fourth Corps by swimming the river at Long Bridge and rafting over his arms on the 28th.

On the morning of June 29 a large portion of a regiment of rebel cavalry, approaching on the New Market road, charged upon a part of