Corps, detachmentear of several army corps, till the army reached the rebel lines and commenced the investment of Savannah. December 13, my command crossed the Ogeechee and Cannouchee Rivers, and marched to attack and capture Fort McAllister. Striking distance had already been reached, a reconnaissance made, and all requisite information gained, when, in accordance with the expressed wish of the General-in-chief, I abandoned my designs of attack, and with my communication with our fleet. This was accomplished before 10 o'clock the same day on which Fort McAllister fell. December 16, the command returned to the vicinity of King's Bridge and went into camp, picketing the Cannouchee and country in direction of the Altamaha. December 17, Colonel Atkins, with upward of 2,000 men of my command, moved, in conjunction with a division of infantry under General Mower, to destroy a portion of the Gulf railroad, and, if possible, the railroad bridge over the Atlamaha. Difficult approaches, and a strong force of the enemy which could to be dislodged, prevented the accomplishment of the latter. The railroad, however, was very thoroughly destroyed and the command returned to camp. December 21, the enemy evacuated Savannah, the army occupied the city, and the operations of the cavalry closed.

In carrying out orders of the commander in chief, and in making the diversions in them indicated, some mistakes may have been made; yet I believe that the principal operations and diversions required of the cavalry have been, throughout the march, successfully accomplished. Certainly it is a fact, that not once has the enemy's cavalry been able to reach the train or flank of one of our many infantry columns. We have three times crossed from left to right, and right to left, in front of our army, and have marched upward of 541 miles since the 14th of November; have destroyed 14,007 bales of cotton, 271 cotton gins, and much other valuable property; have captured two 3-inch rifled guns, and have them now in use; captured and destroyed 865 stand of small-arms; have taken upward of 500 prisoners, and killed, wounded, and disabled not less than 1,500 of the enemy. We have lost 4 officers killed, 6 wounded, and 2 missing; 34 men killed, 153 wounded, and 166 missing.

Before closing my remarks I desire to make favorable mention of my brigade commanders, Colonels Murray and Atkins. Both have at all times faithfully performed the responsible duties that have devolved upon them. Always on duty, attentive to orders, energetic, skillful, and brave; both are educated gentlemen and accomplished cavalry soldiers; both merit promotion.

Lieutenant-Colonel Sanderson and his regiment, Tenth Ohio Cavalry, at East Macon; Colonel Acker and his regiment, Ninth Michigan, and Colonel Jones, Eighth Indiana, when cut off and surrounded near Waynesborough; Colonel Heath and his regiment, the Fifth Ohio, at Buck Head Creek; the Ninety-second Illinois Mounted Infantry, Lieutenant-Colonel Van Burksirk; the Ninth Pennsylvania, Colonel Jordan; the Third Kentucky, Lieutenant-Colonel King; Tenth Ohio, Ninth Ohio, and Ninth Michigan Cavalry, at Waynesborough, December 4, have all, at the various places mentioned, behaved most handsomely, and attracted my special attention. The Second Kentucky Cavalry, Captain Forman, although bout a detachment, at Buck Head Creek and at Waynesborough, did the duty of a regiment, and deserves the highest praise.

Captain Beebe, commanding the artillery, and his lieutenants, Steteson, Fowler, and Clark, have performed their duty well and to the satisfaction of their immediate commanders.