I'm not sure you have your John and Robert "Bob"' straight. See this page for an apparently correct family tree of the Highley's of St Francois county. The John Highley that was likely the father of the Bob Highley of Hildebrand fame is number 16. He is different than the Judge John Webster Highley and his brother Robert Highley both sons of your William Madison Highley ancestor who was indeed married to a Mckee. The tree fits the obits and histories available as well as the early death certificates on line. I've not reworked the tree to find all the primary references though spot checks appear to me that it is solid work.

http://familytreemaker.genealogy.com/users/l/e/n/Cheryl-L-Lengefeld/FILE/0001text.txt

John R