Thanks to both of you for your information. As the records obtained from this site show, my great grandfather, John Pryor Allison was an Asst. Surgeon in the CSA and was examined by a board before getting that title. Prior to that he was living in the same town as his uncle (by marriage), who was a doctor, so I'm thinking that he probably trained with or was mentored by his uncle. He was taken in by his maternal uncle after his mother's death. His father back in AL had no money so I don't think he could have gone north to be educated.