Mary Johnston (1870-1936) was born in Buchanan, Virginia, and wrote a number of books - mainly historical novels, and the most famous of which is To Have and To Hold (1900), which was made into a film. The full text of the novel is here.
I was surprised to see this tatty copy of Sir Mortimer (1904) on sale as I'd never come across any of her books anywhere apart from online. This was on sale in a hardware store in Ridgeway, but again, the full text is available here.
Johnston's books were very popular in other countries as well as the States, and she used her influence to further the cause of women's suffrage. She died in Warm Springs, and was buried in Hollywood Cemetery, Richmond, Virginia.