Ginny describes her great grandparents, who emigrated from England to Zebulon County in 1890. At first, they shied away from buying land there, since it seemed dry and arid. Only after they formed a partnership with a young man named John Cook, another English immigrant, did they resolve to buy land in Zebulon. Together, the three of them worked to convert their land from dry soil to rich, moist terrain. Their techniques were so successful that Ginny’s family still boasts about them nearly a century later.
This passage is a kind of “creation myth” for the Cook family’s farm: an idealized vision of American ruggedness and independence. The myth doesn’t explain how, exactly, the family became so successful, but the implication seems to be that Ginny’s great grandparents and John Cook succeeded because they worked together, and because they got lucky in finding such fertile land (though it has the appearance of being barren).
When Ginny’s great grandparents’ daughter (i.e., her grandmother), Edith, was 16 and John Cook was 23, they were married. Shortly afterwards, they had Ginny’s father. They continued farming the land, cleverly laying “tile” (a kind of tubing that extracts maximum water from below the soil). The tiling has continued to provide for Ginny’s entire family, resulting in good harvests year after year.
Notice that Edith marries John even though she’s much younger than he is: her purpose, in the context of Zebulon’s patriarchal farm culture, is to bear children and unite families through marriage, not to be an independent businesswoman. This is an important, though short, chapter, because it reminds us of the “stakes” of the novel: the vast, valuable, and almost holy land that belongs to the Cooks and gives the novel its title.