Postum - a southern coffee substitute - a left-over from Civil War days when the south didn’t have coffee and the north didn’t have tobacco. In between battles the soldiers would trade the two items between them.
In reply to my own post above. I looked it up and Postum started in 1912 - not during the Civil War.
But from what I read, southerners did get creative making substitutes for coffee. Here is a quote from an NPR link:
“Desperate Confederate soldiers would invent makeshift coffees, Grinspan tells us, roasting rye, rice, sweet potatoes or beets until they were dark, chocolaty and caramelized. The resulting brew contained no caffeine, but at least it was something warm and brown and consoling.”