Well, I know that Milley received a pension for Anderson (Union) bc I have those records, but she wouldn't have been able to file regarding Benton, being confederate, bc she died in Indian Territory in 1889. That explains all of the 1890 confederate pension records I've found (re other family members) since that's basically when they were allowed to apply.
Regarding Francis Marion hospital records. I don't recall the hospital location (one of many regrets), but I know he was in the hospital in Little Rock in Nove 1864 both by Anderson's letter and info in record & he was discharged from duty at Little Rock, hospital April 1865 (Union records) Since I was at the Ft. Smith Library, old library location across from the National Cemetery, maybe it was a Ft. Smith record of him being sick when he was confederate, I don't know. One of those things I'd have to go back & find the book again.
I actually stumbled onto the record bc I was looking for information regarding Nancey Musgrave Young, his sister and wife of Elisha Young, who died at Little Rock Sept 1864. Still have yet to find civilian death records of Little Rock. She and definitely two of her children died between Aug 30-Nov 1864