Henry Bacon Elderkin was my mom's great grandfather. But I don't recognize the other name you gave. Henry's wife was Emma A. Moore b 1841 d 1916. Their child (my mom's grandmother) was Jessie Elnora Elderkin b 1861 d 1951. Jessie married Albert Johnson Nichols. I know (from his autobio) that James D Elderkin had a least a couple of brothers older than he, and maybe he had a sister. Because I can't find his father, I don't know where to look next. Pretty frustrating, but kind of fun!