In addition to the large amount of agricultural products drawn from the upper valley of the Tennessee, they also obtained iron and other materials from the vicinity of Chattanooga.

The possession of East Tennessee would cut off one of their most important railroad communications, and threaten their manufactories at Rome, Atlanta, etc.
When General Buell was ordered into East Tennessee in the summer of 1882, Chattanooga was comparatively unprotected; but Bragg reached there before Buell, and, by threatening his communications, forced him to retreat on Nashville and Louisville.

Again, after the battle of Perryville, General Buell was urged to pursue Bragg's defeated army, and drive it from East Tennessee.

The same was urged upon his successor, but the lateness of the season or other causes prevented further operations after the battle of Stone River.
Last spring, when your movements on the Mississippi River had drawn out of Tennessee a large force of the enemy, I again urged General Rosecrans to take advantage of that opportunity to carry out his projected plan of campaign, General Burnside being ready to cooperate, with a diminished but still efficient force.

But he could not be persuaded to act in time, preferring to lie still till your campaign should be terminated.