From looking through the old newspaper microfilm, I had seen the name Melvin J. Wilcox a number of times and posited that Melvin might be Delia's husband. Finding them buried together answered that question. Melvin was in the newspaper in 1879 because he had just been elected to the position of Clinton County Superintendent of Schools. At this time in our history we had not centralized education and had no state or federal departments of education. In Iowa, there was a County Superintendent who reported to the County Board and whose job it was to oversee and coordinate education activities in the county.
When I got home from Clinton I did a web search for books on the history of Clinton County and found several, including one that had a brief sketch of Melvin J. Wilcox. From the history of Clinton County Iowa by LP Allen:
MELVIN J. WILCOX, County Superintendent of Schools, Lyons; born in Tompkins Co., N. Y., in 1849; his father, Jairus Wilcox, came to Deep Creek Township, Clinton Co., in April, 1864, where he still resides; Mr. Wilcox was a teacher in Clinton Co. for eight years; was for some time Principal of the South Ward School in Lyons; was elected County Superintendent in the fall of 1878. His wife was Miss Delia J. Wise, a native of Fredonia, N. Y.
Also buried nearby are Mary Wise Graul, Jeanette's other daughter and her husband, Jefferson George Graul. Mary and Jefferson had four children: Gertrude, Daniel, Melvin and Julia Graul. Jefferson worked as a station agent for the railroad and for a time they lived in Crawford, Iowa, quite a distance from Clinton. I imagine he had a railroad position in Crawford because they returned "home" to Clinton and were buried there. Their children had a number of descendants and would appear to be the most likely ones to still be in the Clinton area.
One last note, Oscar's sister, Fidelia Emily Langford Pierce, had a daughter Anna Woodruff Pierce who married Charles Godwin. Anna named one of her children after the judge, William George Langford Godwin. And he lived in Webster Groves at the time of his death in 1968.