The Columbian Exchange

The Columbian Exchange: Biological and Cultural Consequences of 1492

Alfred W. Crosby, 1972

This is one of the foundational books of Environmental History. The Columbian Exchange is a term coined by Crosby, describing the bidirectional transfer of biological materials between the Americas and the "Old World" after the voyages of Columbus. These transfers include the export of the staple crops maize, potatoes, and cassava from the Americas to Europe, Africa, and Asia, the importation of domesticated Eurasian animals to the Americas (cattle, pigs, horses, goats, chickens), and most important, the largely unintentional transfer of viruses and bacteria to the population of the Americas. The natives lacked inherited resistance, so pandemics of diseases such as smallpox (and even some illnesses that had been reduced to nuisances in resistant populations) spread virulently. The population of the Americas was reduced by 90% to 95%.

Crosby had a hell of a time getting The Columbian Exchange published. According to his wife, who responded to some emails on his behalf about a decade ago (Crosby died in 2018), he sent the manuscript to a bunch of editors and had no success. She said he was very discouraged. One time he got a returned manuscript in the mail with the single word "ridiculous" scrawled across the first page. Finally a small publisher (the Greenwood Press) Crosby knew who was looking for a new project asked Crosby if he had anything he'd like to see in print. The book began appearing in their ads in journals in 1972. The first reviewer (Wayne D. Rasmussen from the USDA's Economic Research Service in Agricultural History, July 1973) noted the book was controversial and that Crosby ended it "on a note of pessimism", with the idea about impoverishment that would become the thesis of his next book, Ecological Imperialism.

A simultaneous review in the July 1973 William and Mary Quarterly by G.S. Dunbar of UCLA called attention to the syphilis theory (which I suppose is the part that was most eye-catching but distracted the reader from the main point), and objected to Crosby's claim that "we are less for Columbus." In September 1973, another UCLA-based review by Jonathan D. Sauer appeared in Economic Botany. Sauer praised the way Crosby made the main point of the book, but criticized his claim that global plant biodiversity had been diminished. He accused Crosby of falling prey to the "fashionably pessimistic...dogma" about extinction, and said the conclusion was not supported by the evidence provided in Crosby's narrative. That's a fair statement, and probably helps explain why Crosby wrote his second book.

The first use I find of the term Columbian Exchange separate from a review is in a summer 1973 article in Ethnohistory by Henry F. Dobyns, reviewing a different book about Latin American history. Dobyns called it "Crosby's felicitous phrase".

In August 1973, Donald B. Cooper reviewed the book in The Hispanic American Historical Review. Cooper praised Crosby's contribution, but seemed to conclude that the impacts were generally positive: increased life and health for everyone in the long run. I think you have to really close your eyes to the short run in order to make this argument work. Cooper seemed especially annoyed that Crosby didn't cover Brazil more fully -- not as if doing so would have changed the conclusion Crosby came to, but just as a general complaint from a coverage perspective.

In the September 1973 Journal of American History, Richard S. Dunn said the best thing about the book was its "overarching thesis" and "fresh synthesis", but he criticized its lack of subtle exploration of the more detailed complexities and potential exceptions to Crosby's thesis. I don't entirely disagree with that, or with the description of Crosby as a bit of a polemicist. But let's remember, he was kicking down a big door here.

My own assessment is that the book was groundbreaking. It wasn't a perfect book as a book. As several of the reviewers mentioned, it's really a series of essays, revolving around two main ones. The most important, I think, is "Conquistadors y pestilencia", which I actually often have my students read out of JSTOR in its original form. The syphilis part has aged badly and I think it was probably an unnecessary digression from the main point. A play for equivalency that ended up ringing a bit false. Not only is the syphilis thesis unproven, but the effect of this American disease (if it is one) was nowhere near comparable to the effect of Eurasian diseases on native Americans. I think the pessimism about the ongoing effects Crosby takes up in Ecological Imperialism are valid, but I agree he didn't do them justice in this book. It strikes me as exactly the type of thing you'd pull together quickly if an antiquarian bookseller rang you up one day and asked you if you had anything of book length you'd like to see in print. Not really the type of ting you'd send to the editor of an academic press as a finished work.

Actually, it makes me wonder what the book would have looked like, if it had been accepted by an academic press. It may have had some of its rough edges smoothed off, in the editorial process, and become a better book. On the other hand, it may have had some of its rough edges smoothed off, and become a less important contribution to the field. And even after 48 years, there’s a lot of good stuff in it. The thesis is summed up and brilliantly expressed in the title, which has entered the language as a short-hand descriptor for the idea that “the most important changes brought about by the Columbian voyages were biological in nature,” even if not all the people who use the term agree with Crosby that the interaction of the old world and the new “has left us with not a richer but a more impoverished genetic pool.” (xiv, 219)

Crosby’s narrative set the scene by comparing the old world and the new, to show the biological contrasts between them. He traced European conquest and the diseases that spread with (and sometimes ahead of) conquistadors and settlers. Crosby then described the (mostly plant) species that were brought from the Americas to the old world and the (mostly animal) species the Spanish brought to the new. Interestingly, he said most of the really significant species were introduced by the Spanish by 1500, long before North American settlement was begun. After devoting a full chapter to the controversy over the origin of syphilis, Crosby concluded with a look at how American food crops enabled population growth in both Europe and Asia — and continue to, to the present day.

Some of the interesting items along the way include Crosby’s brief discussion of the possible influence of the new world on tradition and religious authority in the old.  “Christian and Aristotelian” belief systems, he said, “proved too cramped to accommodate the New World...men of the Columbian generation discovered that ‘Ptolomeus, and others knewe not the halfe.’” Crosby said an argument about “multiple creations” carried on in Europe until 1859, when Darwin finally laid it to rest, “while also knocking loose a large part of the foundation of traditional Judaism and Christianity.” Crosby’s discussion of the extinction event that wiped out American megafauna has been eclipsed by more recent scientific findings, just as his discussion of the worldwide distribution of blood-types has been overtaken by DNA analysis, but in their day they were powerful examples of interdisciplinary thinking.

Many of the details Crosby included are startling. Cotton Mather’s description of the 1616-17 epidemic that wiped out most of the Massachusetts Indians as a Providential clearing of the woods “of those pernicious creatures, to make room for better growth,” confirmed my impression of the Puritan leader. The idea that “a million Indians lived on Santo Domingo when the Europeans arrived,” and that they were reduced by 1548 to 500, is something you really have to sit with for a while and think about. As is the fact that the “population of central Mexican dropped from about 25 million on the eve of conquest to 16.8 million a decade later.” That doesn’t seem as bad, until it sinks in that it means one out of every three people was dead in just ten years. Sort-of makes all the recent movies about plagues and human apocalypse seem like so many nightmares of a guilty white American conscience.

I didn’t know that when Columbus returned to the Caribbean, he brought “seventeen ships, 1,200 men, and seeds and cuttings for the planting of wheat, chickpeas, melons, onions, radishes, salad greens, grape vines, sugar cane, and fruit stones for the founding of orchards.” And it never occurred to me that some new world species, like the white potato, found their way to places like New England via Europe (brought “by the Scotch-Irish...in 1718”). Other interesting details: “the banana, brought from the Canaries in 1516” and “Cattle...first brought to Mexico for breeding purposes in 1521.” By 1614, “the residents of Santiago [Chile] possessed 39,250 head,” as well as 623,825 sheep. I also didn’t know, but should have guessed after reading about De Soto’s expedition through Florida, that when Pizarro crossed the Andes into Peru in 1540, he brought over 2,000 pigs with him. Somebody should write a history of the conquest that focuses on what it must have been like, moving conquistadors and their pigs through the wild Americas.