MARCH 8-12, 1863. - Expedition from LA Grange, and skirmishes (9th and 10th) near Covington, Tenn.

REPORTS.

Number 1. -Colonel Benjamin H Grierson, Sixth Illinois Cavalry, Commanding First Cavalry Brigade, SIXTEENTH Army Corps.

Number 2. -Lieutenant Colonel Reuben Loomis, Sixth Illinois Cavalry.

Number 3. -Colonel Edward Prince, Seventh Illinois Cavalry.

Number 4. -Colonel R. V. Richardson, First Tennessee Partisan Rangers.

Number 1.

Report of Colonel Benjamin H. Grierson, Sixth Illinois Cavalry, commanding First Cavalry Brigade, SIXTEENTH Army Corps.

LA GRANGE, TENN., March 16, 1863.

CAPTAIN: In accordance with verbal instructions from General Hamilton, I left camp on the 8th instant, with 900 men of the Sixth and Seventh Illinois Cavalry, on an expedition against Richardson and his command. When within about 3 miles of Somerville, our advance came upon a party of rebels, who immediately fled. Encamping here for the night, I sent one company of the Seventh Illinois in pursuit of the enemy, and succeeded in wounding 4 and capturing 1 man and 2 horses. Here I received information of the removal of Richardson's camp, which was confirmed by a communication which I also received from scouts whom I had previously sent out to go into his camp.

On the 9th, at 3 a. m., I proceeded northwest, making a forced march of 35 miles in seven hours, over roads almost impassable from the recent heavy rains. We came upon him on Big Creek, 3 miles southeast of Covington, attacked and completely routed him, killing 22, wounding and capturing over 70, among whom were Captains Cobb and Cushman; also taking and destroying his camp and equipage, commissary and quartermaster's stores, his train, ammunition, and records. I find among the latter over two hundred paroles of Federal soldiers, all his muster-rolls, lists of conscripts, letters, and receipts, giving the names of a number of citizens who have been engaged in smuggling arms, ammunition, and equipments from Memphis and other points for the enemy; also some valuable maps of the country between the Memphis and Charleston Railroad and the Hatchie River. We scoured the country thoroughly in the vicinity of the Hatchie and Covington [Rivers]; also south toward Portersville.

On the 10th, I moved southeast to Mason's Depot, whence a detachment of the SECOND Brigade, under Lieutenant-Colonel Wallace, of the Fourth Illinois Cavalry, reported to me, and whom I ordered to scout the country southwest toward Galloway, Smith's, and Wythe Depot. I encamped near Belmont on the night of the 10th, and 4 miles south of Somerville on the 11th, returning to this place on the 12th, about 2 p. m. I have the satisfaction to report the success of the expedition, having lost none killed or wounded, and 4 prisoners, who have since returned, paroled.

Respectfully,

B. H. GRIERSON,

Colonel, Commanding Brigade.