Williamsburgh, Va., Monday, Dec. 14, 1863.

An expedition composed of six companies of the First New-York Mounted Rifles and three companies of the One Hundred and Thirty-ninth New-York regiment, has just returned from a highly successful raid to Charles City Court-House, situated near the north bank of the James River, and seven miles beyond the Chickahominy. The expedition was under the direction of Colonel R. M. West, the present commander of this post; the cavalry was commanded by Colonel B. F. Onderdonk, and the infantry, which acted as a reserve this side the Chickahominy, by Colonel Roberts.

The infantry preceded the cavalry twelve hours. The Mounted Rifles quitted Williamsburgh at six o'clock on the evening of the eleventh instant, under lowering clouds, and an atmosphere that presaged storm. We made a brief halt at Twelve-Mile Ordinary. After leaving this point, our route lay through dense forests of pine and dreary patches of cleared but uncultivated land. As night and the column advanced, the darkness became terrible, the wind fairly roared through the tall trees, and the rain, so long threatening, fell in torrents. We had two trusty white guides, but you may imagine how serviceable they were, when we could not distinguish a horseman at the distance of three yards, unless, perhaps, he was mounted on a white steed. Still, the regiment moved forward for many miles, keeping closed files, and carefully following the sound of clanking sabres; until, finally, the road, which before had seemed to be in a highly tangled condition, formed a knot like the Gordian puzzle. Here, apparently, fate had a choice bivouac in store for us — but not so Colonel West. The guides lit matches, which blazed for a moment, (just long enough to exhibit our forlorn prospects,) and were then quenched by the rain. Still, we were making a few yards, or rather taking ground to the right. The guide covered his hands with the phosphorus of the matches, and held them up. This did not remind one forcibly of a revolving coast-light, but we persevered. Many of the men lost their way through the woods, two or three officers were missing, but fortunately all regained the column. We pushed on in this manner until about three o'clock, when it being perfectly impossible to proceed another foot, on account of the blackness of all surrounding objects, and the awful condition of the road, (when we found it,) we were compelled to sit patiently in our saddles until daylight, drenched to the skin, and ruminating upon the beautiful moral relation which the soldier sustains toward a grateful country.

At daylight we moved on rapidly, and made up for lost time. We came up with the infantry, and halted a mile this side of the Chickahominy River. They had surprised and captured a small rebel picket. We soon came in sight of the river at Ford's Crossing, and away we went on the gallop. The first rebel picket was discovered on the west bank of the river. They were in a tranquil state of existence, having divested themselves of their superfluous clothing, and lain down to quiet dreams. They were sound asleep. The very doorkeepers of the great and invincible city of Richmond were snoring in their slumbers. After fording the river, which is quite narrow at this place, and the water about up to our saddlebags, we swept onward with drawn sabres, at a light gallop, capturing without resistance four pickets, and keeping a bright lookout in all directions. As we mounted a hill in view of Charles City Court-House, we caught a sight of the rebel camp, and with a loud cheer we commenced the charge. The charge was led by the field-officers of the regiment, with Colonel Onderdonk and Colonel West. It was irresistible. In less than fifteen minutes we captured ninety prisoners, including eight commissioned officers, nearly one hundred and fifty stand of arms, over fifty horses, and a large quantity of forage, commissary stores, camp and garrison equipage.

The rebels were holding the usual Sunday morning inspection in their best clothes, in camp, and made slight resistance, being either entirely surprised or not wishing to injure the few good clothes in their possession.

At the Court-House the rebels made a brief but spirited resistance. They were driven into two wooden buildings, and fired several volleys from the windows, at very short-range. We surrounded the houses, and compelled a surrender. which was formally made by the enemy, after exhibiting a white flag. Sergeant Wood, a brave and faithful non-commissioned officer, was killed in the first assault upon the building. Captain Gregory was severely, but not dangerously, wounded in the thigh. Our entire loss during the expedition was two killed and five wounded.

The rebel officers were, without exception, gentlemen, both in appearance and manner. Had their surprise been less complete, I have no doubt they would have made an obstinate defence. Many of the rebel soldiers were well uniformed, and were mostly armed with the Maynard rifles. The force captured was a part of the Forty-second Virginia, commanded by Major Robinson, who was away at the time on his wedding-tour. It was considered by the rebels a crack corps, they being admiringly styled Plugs.

After destroying their camp, all the arms, accoutrements, and munitions of war, which we could not bring away, we retired leisurely across the Chickahominy. Here the regiment rested awhile. Colonel West sent a small party to secure Diascon Creek bridge. The party arrived just in time to prevent the destruction of the bridge by a small squad of guerrillas, who retired after exchanging a few shots, wounding the guide severely. We arrived in Williamsburgh yesterday afternoon. The fair portion of the inhabitants behaved any thing but amiably when they beheld the result of the expedition, in so many prisoners.

The rank and file of the captured party appeared rather happy, than otherwise, with their sudden escape from rebeldom. One (a nephew of United States Senator Bowden) took the oath of allegiance, and several seemed disposed to do so. The officers, of course, are as bitter as their systematic schooling to pervert the use of the five senses will make any one. Captain Rodgers, in command, owned nearly all the horses and equipments, and he reckons his loss heavily. Among the captured was a young woman in soldier's clothes.

We brought into our lines quite a large number of contrabands. The rebel officers told them they were not compelled to come. We told them they were not compelled to stay. They seemed to value our word most, and came. One of them, an athletic, pure-blooded African, was relating his adventures. He said his master, in Richmond, had sold him for one thousand six hundred dollars, to be sent South. He ran away, and came to his wife, at Charles City Court-House. His master offered two hundred dollars for his capture, and he was obliged to hide. The morning of our arrival at the Court-House, he was lying asleep in the woods, and a little boy came and woke him up, and said that the Yankees had come. He said: Go ‘way, chile; what you want to fool dis nigga for? But just then he heard the firing, and raising up, saw the blue coats of our troops on the hill. I was so glad, dat I come right away, and left all my things.

The following is a list of the killed and wounded in the Mounted Rifles: Sergeant Wood, company H, killed; Corporal Smith, company H, killed; Captain L. B. Gregory, wounded severely in thigh; Sergeant Hendrickson, company H, wounded in three places; private Stoppelbein, company H, wounded; private Johnson, company H, wounded slightly; guide, wounded in arm.

The rebels had three men wounded.

This raid has developed some interesting facts, which I would like to impart, but forbear, on account of their military importance.