December 6, 1862 (Saturday): Conditions in Tennessee and Mississippi

General Samuel S. Cooper

MURFREESBOROUGH, December 6, 1862
General S. COOPER, Adjutant-General:
    General Rosecrans has an army of about 65,000 men in and around Nashville, and some 35,000 distributed along the railroad to Louisville and in Kentucky. General Bragg has about 42,000 men, besides irregular cavalry, which in a few days will occupy Readyville, this place, and Eagleville. We can cross the Tennessee only by ferrying, a very slow process, which Rosecrans would certainly interrupt. The movement to join General Pemberton would, by any route, require at least a month. From the information given me here I believe that the country between the Tennessee and General Pemberton could not support the trains our troops would require for a march through it. If I am right in this estimate, the President's object-speedy re-enforcement of the army in Mississippi-cannot be accomplished by sending troops from Tennessee. To send a strong force would be to give up Tennessee, and would, the principal officers think here, disorganize this army. Rosecrans could then move into Virginia, or join Grant before our troops could reach Pemberton's position, for the Tennessee is no obstacle to him. The passage of the Tennessee is so difficult and slow that we shall be unable to use the same troops on both sides of the river until next summer. Two thousand cavalry will be sent to break up the Louisville and Nashville Railroad, and 4,000 will be employed in the same way in West Tennessee and Northern Mississippi. The latter may delay General Grant.
     Most respectfully, your obedient servant,


    J. E. JOHNSTON.
    General.

Official Records, Series I., Vol. 20, Part 2, Page 441.

Pemberton was closely pressed in Mississippi but Johnston makes a strong case for why Bragg could not reinforce him.  Until the latter stages of the war the Union was largely unable or unwilling to send forces east into Virginia because the Confederates had enough force to at least maintain a credible threat in the region.  Moving Bragg's force, or part of it, to Mississippi would have opened up Tennessee and permitted such a move.  Johnston would keep Bragg in central Tennessee to offset Rosecrans at Nashville and hope Pemberton would continue to maintain a position sufficiently close to Vicksburg to provide support there.