That is most definitely a Confederate soldier holding a DST Sharps. In the item notes it's stated that Mr. Liljenquist purchased it from a man in South Carolina, who in turn stated that the soldier was from Forsyth, North Carolina, which is likely where he found it.
His coat only adds credence to an NC attribution as it's the style of "sack coat" issued by that state from 1861 to mid to late 1862; these had five or six button fronts, squarish fall-down collars, and had colored shoulder facings between the sleeve cap and collar to denote branch of service (black for infantry). An original NC sack coat can be seen in Echoes of Glory: CS on page 144 along with a photograph of a soldier wearing one. Eventually the state issue sack coat would transform into a shorter jacket version of itself and then into an untrimmed honest-to-goodness shell jacket.
I saw this picture a few months ago and immediately started to scour my research sources to find any letter, diary, or memoir that might mention a NC soldier with a Yankee sharpshooter's rifle but came up empty. The American Civil War Research Database lists approximately 1,074 soldiers from Forsyth County, NC and the records seem to be very complete. I doubt that we'll ever know the name of this soldier but there is always hope that this rifle was mentioned in some text somewhere! In the meantime, to my eye and in my opinion, it's the ultimate Confederate image.
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Brian WhiteWambaugh, White, & Companyhttp://www.wwandcompany.com----------------------------------
Randolph Mess, U.S. Sharpshooters