Attached is a link to Missouri Brothers in Gray. A December 1861 letter places Camp Sterling Price in Jacksonport, Ark. By September of 1862 Price's force was in Tupelo, MS and I would not be surprised at all to find the letter came from northeast Mississippi.
https://books.google.com/books?id=aP9QsaFPQCUC&pg=PA91&lpg=PA91&dq=Letter+camp+sterling+price&source=bl&ots=ADjZi7Gl-x&sig=osybC34YXjz7L4LEZVurux4LR5c&hl=en&sa=X&ved=0ahUKEwiZiNzo-KHKAhUUW2MKHTSvCrUQ6AEISDAH#v=onepage&q=Letter%20camp%20sterling%20price&f=false