In 1844, a man whose nom de plume was the unimaginative “A Pioneer” provided a full-page account of Mexico’s “Upper California” in The Farmer’s Monthly Visitor. He presented a land of inexhaustible vegetation and “innumerable herds.” As he put it, “there is no country in the world that offers as flattering inducements to emigrants as Upper California; nor is there a country…so eminently calculated by Nature herself to promote the prosperity and happiness of civilized and enlightened men.” According to this pioneer, the only people in the region were an assortment of mostly non-white people who lived in a “deplorable state of ignorance.” This essay uses primary accounts and secondary sources to examine US perceptions of Mexican California’s resources, economy, and people with the goal of improving the historical contextualization of US expansionism. This essay argues that from the 1810s-1840s, travel writers and commercial interests used new forms of scientific racism circulating through the English-speaking world based on changing conceptions of nature, technology, and resource use to justify conquest. This essay demonstrates that the motivations of involved Americans focused on agricultural wealth, livestock, and maritime possibilities.