Steven, the soldier in question is Pvt. William A. Formby, of Ouachita County, Arkansas. His name appears in various records as Formby, Formley, Farmby, Farinby and Farinly.

He enlisted in Co. H, 19th (Dockery's) Arkansas Infantry, at Caney, Arkansas, on March 3, 1862. He transferred to Co. D, 12th Arkansas Battalion Sharpshooters, on June 24, 1862, and died at Vicksburg on June 27, 1863. I don't know if he died of disease or wounds, but since he died at the height of the siege, I suspect the latter.