In her biography of Alexander Von Humboldt (influential 18th/19th century scientist who has been largely neglected by history), Andrea Wulf convincingly argues that Humboldt’s study of American biology was an important factor in the formation of a pan-American identity that led to Latin American independence from Spain. Up until Humboldt’s observations indicated otherwise, Europeans generally believed (without evidence) that New World flora and fauna, when compared with those of the Old World, were smaller, weaker, and generally inferior.
Colonial control depends on maintaining colonists’ attachments to a faraway motherland over a (arguably much more natural) sense of local community, and one tool employed to maintain this artificial sense of attachment, in the case of the American colonies, was denigration of the land itself. European land, with its big and strong plants and animals is better, and so an attachment to a European country is superior to an attachment to any America-based community. Humboldt’s refutation of European biome superiority allowed Americans to develop a spiritual connection to the land that then enabled the formation of real sense of local identity and pride, which in turn led to the social cohesion necessary for revolution.
In this way, spiritual attachment to land can be radical and anti-imperial. (Of course, attachment to land can also lead to horrible oppressive behavior—no aspect of the human experience with so much power can be purely good.) This quality of spiritual attachment remains true today. Community gardens are punk and anti-authoritarian. City parks help foster a sense of love and municipal kinship. And for me personally, the time I felt most patriotic was while watching the sunset in Yosemite.