There are service records for a Pvt. Elijah M. Powell in Company K,(The Ellisville Invincibles aka Jones County Invincibles), 8th. Mississippi Infantry. See this site for a capsule history of this unit - http://mississippiscv.org/MS_Units/8th_MS_INF.htm
This soldier was 23 years old when he enlisted at Enterprise, MS in 1861 and was originally enrolled and mustered in at Ellisville, MS. His service record indicates he died at the Fair Ground #2 Hospital in Macon, Ga of a gunshot wound on June 18, 1864. Service records are available at this site - http://history-sites.com/research/index.html
It should be noted the sexton records from the Oakland Cemetery indicates this Pvt. E. M. Powell was a member of Company D and died June 19, 1864 in the Fair Ground #2 Hospital in Atlanta, GA.
See - http://www.oaklandcemeteryburials.com/civil_war_genealogy/soldier/1340/display.html
Hope this helps,
Mitchell Sanders