Asleep in France
I was also able (via Ancestry.com) to find Knott Rankin's high school yearbook picture, and another from the Memorial pages of the 1946 University of Maine yearbook:
and the specifics of his military interment record:
which includes his family's address in Rockland. The next step is to fill in more details about his family, and Ancestry.com is happy to oblige with census records and other data: in the 1930 census, Knott Rankin Sr. is identified as 'General Superintendent of Lime company' and other household members are given as wife Lucy, daughters Lucille and Glenna and son Knott. Mother in law Dawdelia Young (aged 80) also lived with them. In the 1940 census, Knott Rankin Sr. is listed as 'VP' of the Lime company; Lucille was no longer living at home, Dawdelia Young was no longer with them, and Knott Sr.'s father Edward Rankin (aged 86) lived with the family. We are well on our way to other family context: there was an earlier Knott Crockett Rankin (born 1831 died 1916) who had a child Knott Crockett Rankin (born 1861 died 1863).
Cyrus Eaton's [1784-1875, and not the Nova Scotia-born industrialist] History of Thomaston, Rockland, and South Thomaston, Maine, from their first exploration, 1605 (two volumes, 1865) makes it clear that many Rankins were to be found in the Rockland area in the 19th century, and tempts us to further genealogical research.
There is a Rankin St. in Rockland, a Rankin Center low-cost housing development, and Rankin's Hardware & Building Supply in nearby Camden.
Lots to do...