Who is K.D. Morgan from Paradise and what is their importance?

Coffee Morgan is called K.D., which is short for Kentucky Derby, the nickname given to him after he won a race in the newly-settled town of Ruby. K.D. fathers an illegitimate child with Arnette Fleetwood, and although she miscarries, the couple later marry and have a family. K.D. is the nephew of Steward and Deacon Morgan.