Hi Elizabeth, Wondering if you've gotten anywhere with your Slayden research. My connection is Armarda B. Slayden who married John H. Fetzer in 1882. They lived in Independence County, Arkansas. I believe that Armarda is the older sister of your James Luther.
Daniel and Lucy are in the census in Calloway County, Kentucky in 1860 and 1870. Daniel died in 1879. I don't know what became of Lucy. I've never located the family in 1880 census. The three children all seem to have ended up in Arkansas somehow, presumably moved to join relatives after the death of Daniel.