James Monroe Hughes

I presume this is your fella:
Birth Info: Aug. 10, 1829 / Parrottsville,Cocke,Tennessee
Death Info: July 15, 1876 / Cole Camp,Benton,Missouri
Spouse Info: Martha Ann Ogan

This matches a draft record of a James Hughes in Saline Twsp Ste Genenieve Co MO in 1863. Also matches a record for a James Hughes First Division MSG Company C 3rd Cavalry. Service was for 4 months 11 days under Capt Valle presumably in 1861/62.

See: http://www.fold3.com/image/192307230/

As I see it your listing of D7 Missouri Southern Militia fits a mis-transcribed 1st Division Missouri State Guard, a fairly common error making a 1 a 7 and vice versa.

John R