[Inclosure Numbers 1.]

CONFIDENTIAL.] HDQRS. DEPARTMENT OF MISSISSIPPI,

Memphis, Tenn., December 18, 1864.

Brigadier General B. H. GRIERSON,

Commanding Cavalry Division, Department of Mississippi:

GENERAL: In accordance with verbal instructions heretofore given you for the purpose of executing the orders which have been received from Major-General Halleck, Chief of Staff, U. S. Army, to break the communications of Hood's rebel army by way of the Mobile and Ohio Railroad, you will move Colonel Karge's brigade of cavalry at early dawn to-morrow morning, proceeding by the north side of Wolf River, and moving via Somerville, demonstrating toward Bolivar, destroying the telegraph line, if any exist between Grand Junction and Jackson; thence moving east and southeast, cutting the telegraph, if one is found, between Grand Junction and Corinth at or near Saulsbury, and thence moving toward Ripley. Twenty-four hours after Colonel Karge moves you will march with all your available effective cavalry force, consisting of Winslow's and Osband's brigades, forming a junction with the advance brigade somewhere in the vicinity of Ripley, visiting, if possible, Holly Springs on the way. You will then strike the Mobile and Ohio Railroad at the most convenient vulnerable point, and destroy it as far and as effectually as you can without unwarrantable risk of your command. You will provide turnpike, combustibles, and tools for destroying the road, and see that your men are provided with not less than 100 rounds per man, and as much bread and other rations as they can carry. It is necessary that you keep your force united, well in hand, and constantly on the alert, with flankers and scouts out, as it is most probable that the enemy is in considerable force at Corinth, as well as in the vicinity of Holly Springs and Oxford and along the Mobile and Ohio Railroad. An infantry force will march at the same time you do, and proceed as far as Moscow, for the purpose of demonstration on Corinth to induce the enemy not to detach from there. A cipher operator will accompany you, and if when near Ripley you deem it safe, it is desirable for you to select all indifferent men and horses and send them back to join the infantry on its return march, and send back with them in cipher such information as you may have. A crushing blow to whatever force the enemy may have in the field near Holly Springs, or detached from Corinth, on your march is very desirable; but it is of the last importance that a complete destruction of the railroad to as long a distance as possible should be effected. Should you in effecting that object find yourself warranted by circumstances in proceeding as far as near Meridian, and then are of the opinion that you could safely make a dash at Cahawba and release our prisoners, the exultation of the nation at such a glorious achievement would be a crowning triumph for you. In returning from your expedition, it is of course preferable for you to come back here; but if you find you way barred by a largely superior force, you can strike the Mississippi at Natchez, Vicksburg, or any other you may be forced to; and if compelled to resort to such an alternative you could even reach Pensacola. I do not wish to restrain you by too definite and exact instructions, as circumstances unforeseen may control your action; but I leave details to your well-known experience, sagacity, and enterprise. You have some fine officers and a good body of men, and I confidently rely on your triumphant success. It is necessary that your movements should be with a celerity limited only by the capacity and endurance