This may be Julia Craddock Brumfield's younger brother, Charles Letcher Craddock (b 1863). From the 1918 context, he resides west of Whittles, near the old Craddock home-place.
The graph displays the other subjects mentioned on the same pages as the subject “Letcher Craddock”. If the same subject occurs on a page with “Letcher Craddock” more than once, it appears closer to “Letcher Craddock” on the graph, and is colored in a darker shade. The closer a subject is to the center, the more "related" the subjects are.