Fifth to Long Bridge on the Chickahominy. At Crump's Cross-Roads met a picket of the enemy, 30 in number. The advance guard charged them the entire distance to Bottom's Bridge, mortally wounding and capturing 1 man who died during the night. The horses of the enemy being fresh, while ours had marched 49 miles, accounts for their escape.

At the bridge we found the enemy posted in a small rifle-pit on this side the river. Sent forward dismounted skirmishers, drove them out and across, where they had a strong earth-work defended by a force of infantry and a squadron of Holcombe cavalry. It was by this time quite dark, and having accomplished the object of the expedition, returned to Baltimore Store, where we bivouacked until 5 o'clock, 28th instant.

I found the force defending the line of the Chickahominy was Wise's brigade or legion. He lay, with most of his force, 2 miles below Bottom's Bridge. His strength was reported by a negro direct from Richmond, and also his camp, at 4,000 infantry (overrated, I think), 8 pieces of artillery, and 900 cavalry. He crossed the river during this night or early on the 28th, with the intention of cutting me off at New Kent Court-House or Slatersville. This was reported by a lady, and from after occurrences I consider the information correct, as my rear guard was attacked while resting at Slatersville, by a considerable force of cavalry, variously stated at from 250 to 500, which fled rapidly on my charging them with one battalion, with the evident intention of drawing me from the strong position I had taken; failing in this, as I pursued with but one battalion, he abandoned his purpose.

In this attack the Fifth lost 1 man killed and 2 slightly wounded. The residents at New Kent Court-House report the rebels loss in same: Killed, 1 major (commanding), 1 orderly sergeant, and 1 private; wounded, 8; making their loss during expedition, 1 officer and 4 enlisted men killed, 8 wounded, and 3 prisoners; total, 16.

I also captured large wagon, with pair of mules and harness, which had lately come from Richmond, and was used for distributing arms. Two rifles and 1 shotgun were found in it and broken up, as were some 7 more of the same kind captured with the prisoners; 4 horses and 5 sabers; these accompany this report.

On the night of the 28th, I encamped at Twelve-Mile Ordinary. Nothing occurring during the night, and returned to camp at this place at 11 a. m., August 29, 1863.

I am, captain, respectfully, &c.,

B. F. ONDERDONK,

Colonel, Commanding Cavalry.

Captain REYNOLDS, Asst. Adjt. General, Yorktown, Va.

Numbers 2. Report of Lieutenant Colonel William Lewis, Fifth Pennsylvania Cavalry.

HEADQUARTERS FIFTH PENNSYLVANIA CAVALRY,
Near Williamsburg, August 29, 1863.

LIEUTENANT: I have the honor to report, in compliance with the order of colonel commanding cavalry brigade, the following detailed account of the part taken by my command in the late expedition: