OXFORD, MISS., December 21, 1862-8 p.m.

(Received December 26, 8.45 p.m.)

The rebel cavalry commanded by Van Dorn made dash into Holly Springs yesterday at daylight, capturing the troops, stores, &c. Their movement from the Yalabusha was very rapid. I heard of their crossing and ordered force to Pontotoc to intercept them, but they traveled as fast as the scouts who brought the news. Next their departure from Pontotoc, going north, was reported. All my available cavalry was ordered in pursuit and are still out. As the rebels outnumber them three to one I do not expect much. When communication was broken with the north I had troops concentrate to resist an attack on Jackson. Do not know the result. If enemy are falling back north of the Tallahatchie I may find it necessary to send forces to Corinth. I would like to send two divisions more to Memphis and join the river expedition with them. This would make it necessary to fall back to Bolivar. The enemy are falling back from Grenada.

U. S. GRANT.

Major-General Commanding.

Major General H. W. HALLECK, General-in-Chief.

HEADQUARTERS DEPARTMENT OF THE TENNESSEE,
Holly Springs, Miss., December 25, 1862.

Colonel J. C. KELTON, Washington, D. C.,:

I am just sending a large wagon train to Memphis after supplies and avail myself of the opportunity (the first now for over a week) to communicate with the authorities at Washington. I had timely notice of the advance of Forrest on the road, in the neighborhood of Jackson, and took every means to meet it. General Sullivan was re-enforced from the army with me, and forces from Corinth, Forts Heiman, Henry, and Donelson sent to co-operate. As the enemy's force was all cavalry and General Sullivan's nearly all infantry it is possible that they have succeeded in evading our troops, so as to do some damage to the railroad, but the extent I have not yet learned. Before any decisive move had been made by General Sullivan against the enemy, or by the enemy on our railroads, communication was cut between us and a formidable move of cavalry from Grenada reported going north.

This force assembled first at Pontotoc, and as Colonel Dickey was out to the east on the Mobile road, with about half of my available cavalry, I concluded that the object was to cut him off. I immediately ordered all the cavalry that could be spared to Pontotoc, and two brigades of infantry with them, with directions to operate from there for the relief of Colonel Dickey. Before these troops got in motion, however, I learned of the rebel cavalry passing north from Pontotoc and of Colonel Dickey passing safely by their rear. I immediately notified all commanders north of me to Bolivar of this move of the enemy, and to be prepared to meet them, and to hold their respective posts at all hazards. Except at this place all have done well, the enemy being repulsed at Coldwater, Davis' Mill, Bolivar, and Middleburg. This place was taken while the troops were quietly in their beds. The commanding officer of the post (Colonel R. C. Murphy, of the Eighth Wisconsin Volunteers) took no steps to protect the place, not having notified a single officer of his command of the approaching danger, although he himself had received warning, as hereinbefore stated. The troops cannot be blamed in the matter, for