8. P. Heintzelman to L. ToomAs, Adjt. Gen. U. 8S. Army, Washington, July 20, 1863

Washington, July 20, 1863.

GENERAL:

I understand that no report has been made of the Crossing of the Potomac at the Long Bridge and occupation of Arlington Heights and Alexandria on the morning’ of the 24th of May, 1861. I was vat that time acting inspector-general to Brig. Gen. J. K. F. Mansfield, commanding the Department of Washington, and as the troops that crossed the bridge moved under my direction, I have the honor to make the following report:

On the afternoon of the 23d, I went with General Mansfield to the Engineer Department, and he there explained to me the plan of operations. This, [ understood from him, did not include the occupation of Alexgndria. Before the troops moved, however, this part of the plan was changed.

The troops which crossed, from the original manuscript now im my possession [were]:

By the Aqueduct.—Staff commanding Captain Wood, now Maj. W. H. Wood, Seventeenth U. S. Infantry. Engineers Woodbury, Blunt, and Houston. Forty-eight pioneers of Fourteenth Regiment New York, Colonel Wood; Sixty-ninth Regiment New York, Colonel Corcoran, and 250 workmen, unarmed; Fifth Regiment New York, Colonel Schwartzwalder; Twenty-eighth Regiment New York, Colonel Burns; one company cavalry; one section artillery.

By the Long Bridge.—Staff commanding Colonel Heintzelman. Engineers Alexander, Prime, and Robert. Twelfth Regiment New York, Colonel Butterfield; Twenty-fifth Regiment New York, Colonel Bryan; Seventh Regiment New York, Colonel Lefferts; Third Regiment New Jersey, General Runyon; one company cavalry; one section artillery.

By steamer.—First New York Zouaves, Colonel Ellsworth. This regiment was encamped on the Potomae below the Eastern Branch, and was landed on the wharves of Alexandria under the guns of the gunboat Pawnee.

Also by the Long Bridge.—First Michigan and Pioneers, Colonel Willcox; one company cavalry; one section artillery.

Captain Brackett commanded the company of cavalry (I, Second Cavalry) that crossed the Long Bridge, and the artillery, 1 think, belonged to Maj. T. W. Sherman’s battery.

During the day I warned the regiments to be prepared to march at a moment’s notice, and at 9 p. m. officers were sent to the colonels, directing them to march their troops to the Washington end of the Long Bridge.

The orders were to enter on the bridge at 2 a. m. on the 24th of May. A few minutes before the hour the head of the column halted at the Washington end of the bridge, and precisely at the hour the troops advanced, the Twelfth New York, Colonel Butterfield, leading. Col. C. P. Stone, ‘in command of the District Volunteers, had made such admirable arrangements that he was enabled to take possession of the Virginia end of the bridge before any alarm was given, and thus prevented the rebels from firing. it. He immediately pushed forward on the different roads strong pickets. On the road towards Arlington they extended as far as the bridge across the canal.

Capt. S. Owen, who commanded some of the District Cavalry, accomCmar.IX} © UNION ARMY ADVANCES INTO VIRGINIA.

panied me, and had with him men well acquainted with the country. The morning was beautiful moonlight. At the forks of the road, where Fort Runyon has since been built, 1 turned the Twenty-fifth New York, Colonel Bryan, to the right.

I gave directions to Captain Owen to lead Colonel Butterfield’s regiment as far as the Four-Mile Run, and it to take post on the right of the road, and then to conduct Colonel Willcox, with the First Michigan, to Alexandria, there to unite with the First New York Zouaves, @olonel Ellsworth, and occupy Alexandria. This was done without opposition, capturing in the town a few rebel cavalry. Some 700 rebel infantry in the town had received notice of the approach of the troops, and were ready to take the cars. They escaped on the Orange and Alexandria Railway, burning the bridges behind them. Our troops pursued a short distance, also burning such bridges as they had spared.

Capt. H. G. Wright, U.S. Engineers, accompanied me. Weadvanced with the Twenty-fifth New York on the Columbia turnpike, and took post between Roach’s and Dr. Antisell’s, where Fort Albany now stands. Captain Brackett’s company of cavalry was posted a short distaifce in the advance on the turnpike. The movement was made so quietly, that the troops had stacked arms an hour before the inhabitants were aware that we had crossed the river.

As far as I can learn, there were only a few men located at the Virginia end of the Long Bridge. The horses of two of them we captured to the right of the Arlington road where it leaves the Columbia turnpike, and a few hours later the men fell into our lines, and were also captured. Communication was immediately made to the right with Captain Wood and to the left with Colonel Willcox.

Thus was commenced the first operation against the rebels in front of Washington.

I have the honor to be, general, respectfully, your obedient servant,

8. P. HEINTZELMAN,

Major-General, Volunteers.

Gen. L. ToomAs, Adjt. Gen. U. 8S. Army, Washington.

No. 3.

Report of Col. O. B. Willcox, First Michigan Infantry.

ALEXANDRIA, VA., May 24, 1861—54 a. m.

Alexandria is ours. One company, Captain Ball, mounted, thirty-five

men and thirty-five horses [captured]. Iregret to say Colonel Ellsworth