Mounted Rifles, and a section of the Fourth Wisconsin Battery, Captain Easterly, in all about 2,500 men, crossed the pontoon bridge across the Appomattox between 12 o'clock and daylight on the morning of the 15th. We came upon the enemy's pickets on reaching the City Point Railroad. We drove them in capturing one line of obstructions, an abatis across the road at the saw-mill; a second line, consisting of a long rifle-pit, manned with three pieces of artillery and an infantry support, commanding the road which debouched from a dense wood. Leaving some carbineers to hold the road until the infantry should come up, I crossed the cavalry over to the Jordan Point road, by a farm road. Here we carried another line of obstructions made by the cavalry picket in the woods, where the enemy fled, leaving the body of a lieutenant in the road. A battalion of rebel cavalry fled upon our approach and we passed on across the Prince George road to the Norfolk road without difficulty. Here we drove in the pickets to the main intrenchments, which we came in sight of about 12 o'clock. Several hours were occupied in reconnoitering the enemy's works and bringing up the column. Several miles of intrenchments were in view, the ground in front was comparatively level and afforded little for or no cover from the enemy's artillery to approach the works. The enemy opened with artillery from five redoubts as soon as we appeared in view, and subsequently two more redoubts were developed on our extreme right. The works were not strongly [manned] with infantry,and I decided to make a demonstration, and, if possible, to get through the line. About 3 o'clock all the carbineers were brought forward, except the First New York Mounted Rifles, which were held in reserve, the First Brigade on the right and the Second on the left. A general advance was ordered and the skirmishers pushed forward to within 500 yards of the intrenchments. As only a portion of the men are armed with carbines, and so many men are required to take care of the horses, our line was really weaker than the enemy's in men, and the skirmishers could not be advanced any farther. We held on until about 5.30 p.m., hoping to see some indications that General Smith had carried the enemy's line on our right, but for several hours no firing had been heard in that direction, the skirmishers were getting short of ammunition,and on the right they were already falling back. I, therefore, ordered the left to retire also, as I had observed indications that the enemy were re-enforcing in that direction. My impression proved correct, as Colonel Spear reported that he could not have held his position any longer. I withdrew my entire command to the Jordan Point road and bivouacked. It was a fatiguing day's work, and the men having had no rest the night before, preparing for the march and fighting and skirmishing all morning, they were in no condition to assault intrenchments, even had they been the proper arm for such service. I had but two pieces of artillery, which were served to the extent of their capacity in drawing the enemy's artillery fire, but were entirely inadequate to the artillery of the enemy, which at one time amounted to twelve pieces.

Our loss was small, as the enemy's artillery was very badly served. Had it been well served we never could have made the advance we did. I regret to announce the loss of Colonel Mix. The conflicting reports concerning him agree only in one particular-that he was left mortally wounded in front of the enemy's works on our right.

The command was occupied on the 16th guarding the left flank of the Army of the Potomac until relieved after dark by the Fifth Corps, when, in obedience to orders, the division, returned to their camps