The "backwards" aspect of the image is because it is an ambrotype or a tintype. Because these were direct images, really negatives, they came out as mirror images. You can also see this in the way the jacket buttons. The dark color (probably blue) was common for TN troops at the beginning of the war because that was what was prescribed for the TN militias.

Herb Peck is (or was) an inveterate collector of CW images, particularly of TN units. I have tried to locate him recently but cannot. Does anybody have a lead on him? He would be in his late 60's and, last I knew, was living in Nashville.