One of my ggggrandfathers was in the 62nd Tennessee, and have done some reasearch on the unit. "Mountain Rebels" describes how the 60th, 61st, and 62nd were formed. These were all East Tennessee regiments. As I recall, the draft had been suspended in East Tennessee, and many of the men joined when the units were formed around October 1862, when the draft was about to be reinstituted, to avoid the stigma of being conscripted. Vaughn's Brigade (as well as Reynolds East Tenessee Brigade) was soon transported to Mississippi; some Confederate authorities felt a move to such a pro-secession state would be a good idea. However, many of the men in the units were (1) unsupportive of secession to begin with and/or (2) worried about leaving their families behind due to internal strife in East Tennessee. The change from the mountains of East Tennessee to the lowlands around the Mississippi River also had a horrible effect on the men's health.
The East Tennesseans arrived in time for Chickasaw Bluff in December 1862. The 62nd was detached to another brigade for the action, and appears to have been one of the three Confederate regiments most responsible for repulsing Sherman's assault.
After the Vicksburg surrender, there was real problems getting the men in Vaughn's Brigade to return to their units after the units were paroled. The Union army had advanced into East Tennessee by that time. On August 27, 1863, Vaughn wrote to Jefferson Davis from Sweetwater. He noted that General Bragg ordered parole camps to be established in East Tennessee for the seven Vicksburg East Tennessee regiments, but had now ordered the units to Atlanta. Vaughn opined the move “will have a bad influence, as they are not yet exchanged and their homes are threatened. I fear one-half of them will not leave East Tennessee.” Vaughn also discussed how General Bragg and General Buckner were falling back, and that “A perfect panic now exists in this department."
My own ggggrandfather apparently never returned, and actually ended the war in a Union regiment with his brothers. Reynolds' and Vaughn's brigades were combined into a mounted infantry unit. It seems to me they remained mainly in western Virginia. Some of these men were with Davis as he tried to escape west after the collapse of the Confederacy, and made it as far south as Georgia.