People are not the only immigrants in the world. The age of discovery began a transatlantic exchange of animals, plants, and germs. Most of us know about the devastating effects of Old World diseases; the worst thing the white man ever gave the red man — worse than war or liquor — was smallpox. The New World returned the favor with syphilis. “We have many pocky corses now-a-days,” says the gravedigger in Hamlet, “that will scarce hold the laying in.” Agriculture profited by the exchange. Horses, livestock, and fruit trees went west, corn, potatoes, and tomatoes east. But wilderness — the world we mistakenly call natural — changed too. We regularly read fun fillers or scare stories about the escape of strange species: parakeets living in Green-Wood Cemetery in Brooklyn, killer carp itching to break into the Great Lakes. But the process began centuries ago.
Europe was slowest to leave its mark on North America. Spain’s vast Latin American empire was rocking and rolling by the mid-1500s. Lima and Mexico City each boast a university founded in 1551, months apart (Lima nipped in just ahead). The pope had long before that assigned Brazil to Portugal. The nations that colonized the north — France, Holland, England — were slower to move, and their footprint for many years was relatively light.