Leaving Vicksburg at daylight on November 23, the expedition, consisting of 2,200 cavalry, eight pieces of artillery, and a pontoon train, arrived at Big Black River at 1 p. m. same day, and laid the pontoon bridge over the Big Black. On 24th the Eleventh Illinois and Second Wisconsin Cavalry, Major Dale, Second Wisconsin, commanding, crossed and proceeded scouting toward Jackson, returning and recrossing at night without meeting the enemy, although subsequent information satisfies me that some 3,000 of the enemy were in line of battle on the Jackson road to contest the advance. The bridge was taken up, started back to Vicksburg under escort, and the column moved toward Yazoo City on morning of 25th, marching thirty-seven miles that day, bivouacking near Mechanicsburg; marched thirty-six miles on 26th, bivouacking near Benton; struck the Big Black bridge on 27th, and reached Yazoo City on 29th. The last of the troops returned to Vicksburg to-night, December 4. The entire plan, as detailed by me to yourself and General Davidson, was completely carried out by Colonel Osband, completely deceiving the enemy, and the expedition was a signal success; he brings back more recruits than his entire loss in effective force, and reports the destruction of the very important long railroad brigade and trestle at the crossing of the Mississippi Central Railroad over the Big Black River, near Canton, Miss., thus cutting off the supplies and stores accumulated at Jackson, Miss., from Hood's army, and severing railroad communication between Corinth, jackson, Meridian, and Mobile; this-together with the burning of piles and store -houses full of corn and grain, and 30 miles track, wagon road bridge over Big Black, Vaughn Station (railroad depot and buildings), Picket Station (railroad depot and buildings), Goodman Station (railroad depot and buildings), 2,600 bales of C. S. cotton, 2 locomotives, 4 cars, 4 stage coaches, 20 barrels salt, $166,000 worth of stores at Vaughn Station-makes it one of the heaviest blows lately dealt the rebellion, as it directly affects the efficiency of Hood's army now on the Tennessee River, dependent on this railroad and these supplies.

Information just received from a deserter shows that there were at least two brigades of cavalry and be brigade of infantry closing in on Colonel Osband at Yazoo City, thus confirming his impressions of the superiority of the rebel forces.

Requesting that Colonel osband's well-deserved mention of officers and commands may receive the attention of the major-general commanding division,

I have the honor to be, sir, very respectfully, your obedient servant,

N. J. T. DANA,

Major-General.

I cannot close this report without calling attention to Major J. B. Cook Third U. S. Colored Cavalry, for some time past in command of the regiment. The intelligence, industry, and devotion to the service, with the long list of gallant deeds constantly enacted by Major Cook, entitle him to consideration, while in my judgment the best interest of the service demand his raid advancement. The charge over the railroad trestle-work and bridge by dismounted cavalry, led by Major Cook, was one of the most dashing and heroic acts of the war. As an act of simple justice, I recommend his immediately promotion to the lieutenant-colonelcy of his regiment now vacant.

N. J. T. DANA,

Major-General.

Lieutenant Colonel C. T. CHRISTENSEN,

Asst. Adjt. General, Hdqrs. Mil. Div. West Miss., New Orleans, La.