Wednesday, September 24, l862.
Major General JOSEPH HOOKER,
Commanding First Corps d'Armee U.S.A., Washington City, D.C.
GENERAL: I have the honor to report that, pursuant to orders received on September 16, I crossed the Antietam at Keedysville with my command; there, threw out an advance of one squadron, under the command of Captain S. Jones, with orders to advance cautiously and ascertain the position of the enemy, which he did to my satisfaction — driving in their pickets until he was met by a shower of grape and canister from a masked battery, when he retired in good order and without casualty, except the loss of one horse.
At night I placed two squadrons as pickets to protect our flank and rear, they remaining upon that duty of twenty-four hours. At daylight on the morning of September 17, I dispatched one company, under the command of Captain Gary to bring up the ammunition train, which duty was performed to my satisfaction. At the same time another company, under Lieutenant Davis, was detailed for scouting duty.
These details left under my immediate command one squadron and one company, comprising in all about ninety men.
At the commencement of the battle I received your orders to form a line in the rear of the infantry to take car of the wounded, as they should be brought from the battlefield, so as to permit the return of the bearers to their respective commands without loss of time.
In performance of the various duties consequent upon your orders, I was ably assisted by Captain George Johnson, Lieutenant William E. Miller, and Captain Hess, and Adjutant Abel Wright.
In regard to the orderlies who were specifically detailed for your service on that day, it will afford me much pleasure to forward their names as soon as I can obtain them.
I have the honor to be, very respectfully,
SAMUEL W. OWEN,
Lieutenant-Colonel, Commanding Third Pennsylvania Cavalry
Source: Janet Hewett, ed., The Supplement to the Official Records of the Union and Confederate Armies, 100 Volumes in 3 Parts, Wilmington (NC): Broadfoot Publishing Company, 1994-2001; Part 1, Vol. 3, pp. 514 - 515. From Box 9, Folder C, Joseph Hooker Collection, The Huntington Library, San Marino, California