P. Sf. Geo: Cooke to Fred. T. Locks, July 3, 1862

Sir: I have the honor to report the operations of the Cavalry Reserve in the battle of June 27. Its extraordinary duties and exposure for the day or two previous in covering the right and rear of the army had caused the detachment of about half of my forces, under BrigadierGeneral Emory, and which that morning were ordered to retire on a different line.

In obedience to orders I left Cold Harbor, and arrived on the field of battle about the hour the enemy began his attack. I selected a position and disposed my force in contiguous close columns. Of the First Brigade there were present two and a half squadrons Fifth Cavalry, and three squadrons Lancers, Colonel Rush; of the Second Brigade, Colonel Blake, only two skeleton squadrons First Cavalry, and the provost guard, under Lieutenant-Colonel Grier.

“About 6 o’clock p.m. I observed all the infantry of the left wing, in rear of which was my position, giving way, and three batteries, which in reserve positions had been silent the whole day, opened a violent fire upon the advancing lines of the enemy. Without orders, of course, I instantly conducted the Fifth and First Cavalry to the front, and deployed them in two lines a little in rear of and just filling the interval of the two right batteries. This was under a warm fire of musketry and shell. I instructed Captain Whiting, commanding the Fifth, to charge when the support or safety of the batteries required it. Linstructed Colonel Blake to support the Fifth and charge when necessary.

I then galloped to the left, and placed the Lancers on the right of the third battery—Second Artillery, Captain Robertson. I found it limber42 ‘HE PENINSULAR CAMPAIGN, V. A. [Cuar. XXIIt.

ing, having been wholly unsupported. I ordered the fire reopened. The position was not very good for the matter in hand, but the renewed fire was continued until the rest of the army had retreated, and the enemy was nearer the only line of retreat than we were. I then ordered this battery to retire, and when it was all to the rear I fell back about

Ninth Massachusetts—and my First Cavalry, in line on the slope, a little in their rear. I then formed the Lancers, and ordered the First Cavalry to take post on the left of the infantry, but by an unhappy misconception of the order they advanced close upon their rear. While they were in motion Colonel Childs, Fourth Pennsylvania Cavalry, reported to me with an only squadron of his regiment in hand, expressing a noble devotion. I sent him to join the left of the First, and this was done with a precision and bravery which would have honored veterans. Thus was withstood, under a hot fire of infantry, the advance of the enemy at the brow of the hill. Then a battery of ours, which had been posted 4l0 or 500 paces in our rear in the obscurity of evening and of smoke and dust, opened a fire of shrapnel, which fell among us instead oftheenemy. I then ordered the cavalry to retire, having been informed a second or third time that General Porter had ordered a retreat, and which he has informed me he had not done. The infantry were near the cover of a ravine leading to the rear, and retired at the same time.

Having reached the hollow under anid safe from the fire of our battery, [formed once more the First Cavalry and the Lancers. The enemy made no further advance.

It was a hard duty given this half of the Fifth Cavalry. Emulation of the habitual devotion of our artillery was a strong motive. I was determined on this occasion they should not be sacrificed nor lose their guns.

The charge of the Fifth Cavalry failed to be carried home. The left squadron had but one officer present, the gallant Captain Chambliss, and when he fell it broke and threw the rest of the line into disorder. Its success, beyond enabling the batteries to get off, was impossible. It lost most severely, and did not rally. The First Cavalry then retired in line, covering the retreat of the batteries. Its subsequent action has been given.

The Sixth Pennsylvania (Lancers), under its gallant colonel (Rush) and his fine officers, performed its duty handsomely. The reports of commanders are inclosed, with the lists of casualties. These show a loss of killed, wounded, and missing of 9 officers, 92 rank and file, and 128 horses. .

I again have the pleasure of commending the bravery and ability with which my staff (Capt. W. Merritt, Second Cavalry; Iirst Lieut. James P. Martin, Seventh Infantry, and Frank Beach, Fourth Artillery) performed their duties.

; Privates B. i. King, Company D, Sixth Cavalry, and Adam Romer, Company B, Fifth Cavalry, performed services above their position as orderlies with intelligence, bravery, and promptness.

Very respectfully, your obedient servant,