HEADQUARTERS DEPARTMENT OF THE OHIO, Knoxville, Tenn., February 22, 1864.

Major-General GRANT,
Commanding Mil. Div. of the Mississippi, Nashville, Tenn.:

GENERAL: Your letter of the 16th, relative to the concentration of troops for the spring campaign, did not reach me until yesterday. I have no doubt of the wisdom of the plan you suggest of sending a column from Kentucky into West Virginia, provided my force here can be made strong enough without the aid of the troops necessary to form that column. Its successful execution might fairly be expected to result in the destruction of Longstreet's army. The best place of rendezvous for a force intended to join me here early in the spring is Carthage, on the Cumberland. The road from that place to this is good, and troops can be supplied there by water. The proposed expedition from Kentucky should, in my opinion, move through Pound Gap to Estillville. A cavalry force, moving by that route with sufficient infantry and artillery to force its way through and to cover the retreat of the cavalry after its work is finished, would probably accomplish, in conjunction with a force moving up the Holston Valley, the full result desired. It does not appear to me that a force moving from Cumberland Gap could be expected to accomplish the same result. Yet it would be valuable in conjunction with my movement from this place in enabling me to turn the enemy's right and open communication with Cumberland Gap. It would not, however, be wise to sacrifice anything of the essential strength of this column for that purpose. I would rather rely upon a rapid movement of a powerful force from this point to turn the right of Longstreet's present position that to divide the force in the manner proposed. If instead position than to divide the force in the manner proposed. If instead of a movement from here upon the enemy's right flank any other be adopted, a detachment upon his right could be sent from here nearly as well as from Cumberland Gap. On the other hand, to place a force at or in rear of Cumberland Gap would probably be a wise precautionary measure against a movement by the enemy into Kentucky if he should be prepared for aggressive operations before we are.

The road through Pound Gap is not so good as that through Cumberland Gap, but is quite practicable for cavalry. It is barely passable for artillery and wagons in the dry season.

It would be late in the spring before infantry and artillery could move by either route. I am now compelled to use pack-mules to supply the troops at Cumberland Gap from Camp Nelson. A force intended to move by either route should rendezvous at Camp Nelson. It could hardly start from that place before the 1st of May. This would delay the movement from this place until the 15th or 20th of May. My impression is that a force may be concentrated here [and supplied] sufficient to drive Longstreet out of the country at least a month earlier.

If you can calculate with certainty upon giving me here a sufficient force to insure my success. I think it would be wise by all means to rendezvous a force of infantry and artillery at Camp Nelson for the purpose you suggest; but if there is any doubt of your ability to make this column strong enough to act independently of the other, it would be better to concentrate the troops you propose to give me at Carthage. From that place they can be brought to this at any time I may require them.