Read the passage from Sugar Changed the World. Eventually, I visited Guyana to find out the fate of our house. As our car passed old sugar estates, and I saw the palm trees bending against the wide sky, the lush cane growing in thick, shiny rows, the villages, which were really parcels of land surrounding the important estates, I realized that sugar had been the entire reason for this country's existence. Every now and then an old boiling house—where the cane is processed into crystals, molasses, and rum—would show itself on the flat landscape, cropping up like a hulking ghost. How do the details about Guyana reveal the author’s purpose?