Hi! I have a John Grubbs in Knoxville, TN. I don't know much about him. Really the only thing similar in our posts is that he lives in Knoxville and you put Cowden as a surname. I have that his wife is Eva. Kids Maude Grubbs and Joseph Horton Grubbs. I know more family for Maude and Joseph. I have that Joseph Horton Grubbs married Ora Irene Cowden. I hope I helped.. Please reply if you have/need info.