MEMPHIS, TENN., March 15, 1863.

Brigadier-General TUTTLE, Cairo:

Inform Asboth of the news from Fort Donelson, and direct him to re-enforce that post either by land or water, as he best can. This to be done if it can be confirmed that the enemy are near the fort.

S. A. HURLBUT.

BEFORE Vicksburg, March 16, 1863.

Major General J. B. McPHERSON:

I returned this morning from a reconnaissance some 30 miles up Steele's Bayou. Admiral Porter and myself went in a large gunboat, preceded by four of the old "turtles. "

These boats are pushing on with all dispatch to get into the Yazoo. It is important that a force should get in there with all dispatch. I have information direct from Vicksburg and the Yazoo River, both from persons who have been there and from late papers, that our gunboats had been down to Greenwood and exchanged a few shots with the fort at that place. The enemy have sent up re-enforcements from Vicksburg, and some more guns. If we can get our boats in the rear of them in time, it will so confuse the enemy as to save Ross' force. If they do not, I shall feel restless for his fate, until I know that Quinby has reached him. Quinby will have the most abundant force for that route with his DIVISION and that of John E. Smith. I am now almost sorry that I directed the latter to join him. It seems impossible to get steamers of the class we want. I sent long enough since for them to have received them from Pittsburgh, if necessary.

The route through Bayou Macon my prove a good thing for us yet in some operation. But this one, to get all our forces in one place, and that where it will be in striking distance of the enemy's lines of communication north, is the most important until firm foothold is secured on the side with the enemy. It may be several days before I will move Logan. His freight had better be kept aboard, but the men might stay on shore as much as possible.

U. S. GRANT.

BEFORE Vicksburg, March 16, 1863.

Major General W. T. SHERMAN, Comdg. Fifteenth Army Corps:

You will proceed as early as practicable up Steele's Bayou and through Black Bayou to Deer Creek, and thence with the gunboats now there, by any route they may take to get into the Yazoo River, for the purpose of determining the feasibility of getting an army through that route to the east bank of that river, and at a point from which they can act advantageously against Vicksburg.

Make such details from your army corps as may be required to clear out the channels of the various bayous through which transports would have to run, and to hold such points as, in your judgment, should be occupied.

I place at your disposal to-day the steamers Silver Wave and Diligent, the only two suitable for the present navigation of this route. Others will be supplied you as fast as required and they can be got. I have given directions, and you may repeat them, that the party going on board the steamer Diligent push on until they reach Black Bayou,