Numbers 227. Reports of Colonel Randall L. Gibson, Thirteenth Louisiana Infantry, commanding Thirteenth and Twentieth Regiments and Adams' brigade.

TULLAHOMA, TENN., January 11, 1863.

SIR: I beg leave to submit the following report of the part taken by the Thirteenth and Twentieth Louisiana Regiments in the action of 31st:

We were posted on the right of Adams' brigade, the right of the regiment resting near the river, and the two left companies overleaping the rail track. We advanced in line of battle until we reached the houses destroyed by fire, and the point at which the ground swelled into a considerable hill, stretching toward the line of the enemy, and where the river turned off quite abruptly to the right. We here halted, in order that disposition might be made to pass the obstacles in front of us. The regiments next to the Thirteenth and Twentieth (the Sixteenth and Twenty-fifth) having been thrown into column, we then advanced up the ascent, leaving quite an unoccupied space between the right and the river. Ascending the elevated position, I discovered the enemy moving troops rapidity up the river, on our right, and placing them also in ambush in the corn-field on our front. Riding to the rail track, I saw, not more than 50 yards distant, a line of battle of the enemy, using the embankment as a breastwork and to conceal them from our troops on the low ground to our left. The line of battle on the rail track, as the line of battle along the river bank, was at right angles to our advancing line, and the enemy reserved his fire until the command was flanked. So soon as I discovered the disposition of the enemy, I rode across the railroad and informed General Adams. It was, however, too late to accomplish a time change in our position. Moreover, from the moment of our advance, in the face of the enemy, his artillery had kept a constant fire upon us, while the fire of his infantry was reserved, rendering it more difficult, in addition to the broken nature of the ground, to make new dispositions. The first fire we received was from the river bank, and directed upon the infirmary corps of the regiment, posted considerably in our rear. I immediately moved the regiment double-quick by the right flank toward the river, but, finding a front as well as a flanking fire open upon us, I commanded a halt, and determined to contest the field. The right of the regiment stood firm for a few minutes, but under the combined fires gave way. The men naturally faced the direction in which the severest fire came, and this caused some confusion. We were enabled to hold the left in its position, the fence in its front affording some protection. I felt the necessity of holding our position until the balance of the brigade, already falling back, should pass the point at which the enemy was pressing us on the right. Should this be prematurely lost, there had been a very much larger force than the rest of the brigade, with every advantage of position, covering its entire front and enveloping its right flank. I called upon Major [J. E.] Austin to form on my line and assist in its defense. In a few moments he disposed his battalion of sharpshooters as I suggested. We were successful in holding the high ground on the right of the railroad until the left portion of the brigade, driven back by a storm of artillery and infantry fire on its front and flank, had reached a point beyond our line. The ground was much broken. A continuous line of battle could not be formed on the hill, and this was one of the main reasons why there was some apparent irregularity in falling back.