Kenneth,

My GG grandfather's name was definitely William Angus Russell and he would have been from Mississippi. The family story goes that he first went into the Confederate army as a doctor, but suffering from depression after so many amputations, he quit the medical corps and enlisted as a private soldier in a mounted unit as quartermaster, serving around Port Hudson during the siege. (Family stories usually contain a grain of truth.) In his journal he says nothing about his unit, just the story about looting a Yankee supply train. He would have been in a Mississippi unit, unless transferred to to help fill one from Arkansas. Still depressed enough to make an attempt at suicide, he taught school for a while after the war, but then put up his shingle again and began practicing medicine. He died of smallpox contracted from a patient in the 1880's. I lost all my 30 years of family research records in the tidal wave from Katrina, and the first disk of my Family Tree storage disks won't run.
So exact dates off the top of my head are impossible. I have located a computer generated paper copy of my family records, and though it is abbreviated, I can maybe rebuild from that. The Russells originally came from South Carolina by way of Tennessee. Thanks again,

Bob