George, my records on Dr. J. O (Jacob Oscar) Magee match yours. He was born in 1831 Marion County, MS. Died 1890 in Miller County, Arkansas. Married Julia Foxworth Ca. 1858. I have no
info if he was an official CSA Doctor. He seems to be too young to be assigned to Quinn's 2nd militia. I think you're right about all Doctors throughout the State being overwhelmed as the Shiloh wounded kept
being moved further south down the rail line. I'll include more details from my records via email. To simplify, Dr. Jacob O Magee is my cousin, & if your uncle , we are related. My records also reflect that his wife Julia Ann Foxworth, was born 1834: Marion County, MS. Julia was previously married to a Allen Barnes & had two children. I have no records on the specifics of that marriage.