CONFIDENTIAL.] WASHINGTON, D. C.,

February 17, 1864.

Major-General GRANT, Nashville, Tenn.:

GENERAL: Your letter of the 12th instant is just received. I fully concur with you in regard to the present condition of affairs in East Tennessee. It certainly is very much to be regretted that the fatal mistake of General Burnside has permitted Longstreet's army to winter in Tennessee. It is due to yourself that a full report of this matter should be placed on file, so that the responsibility may rest where it properly belongs.

The condition of affairs in East Tennessee and the uncertainty of General Banks' operations in Texas and Louisiana have caused me to delay answering your former communication in regard to the operations of the campaign. In one of these you suggest whether it might not be well not to attempt anything more against Richmond and to send a column of 60,000 men into North Carolina. In the first place, I have never considered Richmond as the necessary objective point of the Army of the Potomac; that point is Lee's army. I have never supposed Richmond could be taken till Lee's army was defeated or driven away. It was one of Napoleon's maxims that an army covering a capital must be destroyed before attempting to capture or occupy that capital. And now, how can we best defeat Lee's army-by attacking it between here and Richmond, on our shortest line of supplies, and in such a position that we can combine our whole force, or by a longer line and with a force diminished by the troops required to cover Washington and Maryland?

Such movement through North Carolina alluded to by you, and also one from Port Royal on Savannah and into Georgia, have been several times suggested here, and pretty fully discussed by military men. It is conceded by those suggesting these expeditions that neither of them can be safely undertaken with a less force than that estimated by you, viz, 60,000 effective men. Some require a still larger force.

If we admit the advantage of either of these plans, the question immediately arises, where can we get the requisite number of troops?

There is evidently a general public misconception of the strength of our army in Virginia and about Washington. Perhaps it is good policy to encourage this public error. The entire effective force in the fortifications about Washington and employed in guarding the public buildings and stores, the aqueduct, and railroads does not exceed 18,000 men. We have a few thousand more in the convalescent and distribution camps, and in the cavalry and artillery depots, but thee are mostly fragments of organizations, temporarily here for equipments and distribution, and could contribute very little to the defense of the place. This force is, therefore, less than one-half of what General McClellan and several boards of officers recommended as the permanent garrison. Considering the political importance of Washington, and several boards of officers recommended as the permanent garrison. Considering the political importance of Washington, and the immense amount of military stores here, it would be exceedingly hazardous to reduce is till further.

The effective force of the Army of the Potomac is only about 70,000. General Meade retreated before Lee with a very much larger force, and he does not now deem himself strong enough to attack Lee's present army.

Suppose we were to send 30,000 men from that army to North Carolina, would not Lee be able to make another invasion of Maryland