Columbian Exchange

The Columbian Exchange

Alfred W. Crosby, Jr.
The Columbian Exchange: Biological and Cultural Consequences of 1492

For environmental historians, Alfred Crosby's
The Columbian Exchange is one of those books that must be read. Although the book is now 43 years old and contains some outdated information (for example, Crosby based much of his argument on blood types because DNA analysis wasn’t yet available), the basic idea has stood the test of time. Crosby’s thesis is summed up 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.” There’s pretty widespread agreement on the significance of biological change after European contact with the Americas, although not all the people who use Crosby’s term agree with him 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). I've been using a reading from this book in my EnvHist class the past couple of years. I may be changing to a passage from 1491 next time, but I still think The Columbian Exchange is a founding text of Environmental History.

Crosby sets the scene by comparing the old world and the new, to show the biological contrasts between Europe and the Americas. He describes European conquest and the diseases that spread with (and sometimes ahead of) conquistadors and settlers. Crosby then describes 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 says most of the really significant species were introduced by the Spanish by 1500, long before North American settlement was begun (108). After devoting a full chapter to the controversy over the origin of syphilis, Crosby concludes with a look at how American food crops enabled population growth in both Europe and Asia -- and continue to do so, 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 says, “proved too cramped to accommodate the New of the Columbian generation discovered that ‘Ptolomeus, and others knewe not the halfe.’” (9) Crosby says an argument about “multiple creations” was 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” (14). Crosby’s discussion of the extinction event that wiped out American megafauna has probably 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 great examples of interdisciplinary thinking.

Many of the historical details Crosby includes were probably startling to readers in the pre-Zinn 1970s. 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,” sheds new light on the Puritan leader (41). 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 (45). The “population of central Mexican dropped from about 25 million on the eve of conquest to 16.8 million a decade later” (53) 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. Numbers like these fueled the fire for later authors like Howard Zinn. For me they call to mind all the recent movies about plagues, zombies, and human apocalypse; like so many nightmares of a guilty white American conscience.

Before reading Crosby, I didn’t know that when Columbus returned, 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” (67). And it never occurred to me that some new world species, like the white potato, found their way to places like New England after becoming staples in Europe (brought “by the 1718” 66). Other interesting details: “the banana, brought from the Canaries in 1516” and now the cash crop of Central American banana republics (68). “Cattle...first brought to Mexico for breeding purposes in 1521” (87). But by 1614, after less than a century, “the residents of Santiago [Chile] possessed 39,250 head,” (91) as well as 623,825 sheep (94). 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 (79). 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.

Crosby first addressed the idea that disease was an central force in early American history in a 1967 journal article called “Conquistadors y Pestilencia.” Crosby later said he had “stumbled into environmental history through the backdoor of epidemiology.” Of course, there was no such field as environmental history at the time, and Crosby helped create it. “Conquistadors y Pestilencia” is about the Spanish conquest of the Aztec and Inca Empires. “How did Hernán Cortés do it?” Crosby asked. “Well, he didn’t. Old World smallpox did,” he answered.

“When the isolation of the Americas was broken, and Columbus brought the two halves of this planet together, the American Indian met for the first time his most hideous enemy – not the white man or his black servant, but the invisible killers which these men brought in their blood and breath,” wrote Crosby in 1967. Over the next couple of years, Crosby expanded the article into a book and coined the term that has become the accepted name of this phenomenon.

Crosby tried for several years to interest publishers in his radical book, without success. I had an opportunity to talk with Prof. Crosby and his wife recently via email, and they both recalled the most memorable rejection letter he received consisted of the single word “Nonsense.” Crosby finally attracted a publisher in 1971, when the Greenwood Press, an antiquarian bookseller that usually printed out-of-print titles, asked him if he had anything book-length he’d like to see in print.
The Columbian Exchange was published in 1972, and slowly began to attract the attention of historians over the next several years.

Early reviews were generally favorable, although some reviewers failed to grasp Crosby’s point. One article in a major academic journal, for example, described disease decimating both old world and new world populations. Crosby’s book didn’t say this had happened, and it had not. The only disease that may possibly have crossed from the new world to the old, Crosby had claimed, was syphilis. Although a feared killer, syphilis did nowhere near the damage to Europe that smallpox, plague, and other Eurasian diseases did to American populations.

Over time, Crosby’s thesis and his approach to history attracted historians with similar interests in biological and ecological issues, and
The Columbian Exchange became one of the founding texts of a new field. Unlike mainstream historians, who mostly rejected the pessimistic conclusion of Crosby’s book, environmental historians were willing to consider the possibility that the Columbian Exchange was not over. Crosby continues to argue the events of the sixteenth century were “simply an early phase in a slide toward worldwide biological homogeneity,” and that this process is “continuing, even accelerating.”

The idea that decreasing biological diversity is bad is essentially a scientific judgment rather than a historical one. And as
Charles C. Mann has recently observed, it's not a conclusion shared by all scientists. So it’s no surprise that some historians disagree. One of the things that seems to define environmental history as a field is a general belief that these types of scientific judgments are valid and should be taken at least as seriously as cultural, political, or economic data. The general idea that biological processes influence history has gained support over the years, and even entered the mainstream. Jared Diamond’s 1997 bestseller Guns, Germs, and Steel followed (and borrowed without attribution from) Crosby’s less well-known 1994 book Germs, Seeds, and Animals: Studies in Ecological History. Charles C. Mann’s bestseller 1491: New Revelations of the Americas Before Columbus acknowledges its debt to The Columbian Exchange, uses the term, and even tells the story of the author’s interactions with Alfred Crosby. 1491 is brilliant -- I'll have more to say about it very soon.

1491 and Historians

In the process of reading 1491, writing a bit about it, and deciding how I'm going to use it in my next EnvHist class, I've run across some environmental historians and some others who -- how to put it -- seem less enthusiastic about Mann's book than I am. This led me to wonder how academics responded to it when it came out. It was a big hit with readers and popular reviewers, as I already mentioned. But how did experts and scholars respond?

I've read several reviews, and most of them are pretty positive. However, this may be due to the steamroller effect of
1491's popular and commercial success. So what did academics say amongst themselves? Luckily, the prominence of the book created an opportunity for several panels and fora in the years after its publication. The transcripts of these events provide an interesting look at the relationship between academic research and popular writing.

Autumn 2004 issue of the Journal of the Southwest featured an article composed of the reactions of several of the researchers Mann relied on, including Henry F. Dobyns, William M. Denevan, and William I. Woods, and also a response by Mann. These scholars were mostly pleased with the popularity of 1491 and its success getting their ideas in front of general readers. And according to their responses in the article, they seemed pretty satisfied with the accuracy of Mann's portrayal of their ideas.

Another forum, sponsored by the American Geographical Society and published in the
Geographical Review in July 2006, discussed 1491 in even greater detail. ( and the eight articles that follow)

In his review, geographer Jerome Dobson quoted his colleague Dan Gade at a recent CLAG (Conference of Latin American Geographers) conference forum on
1491, asking simply "What's wrong with us? Why can't we [geographers] write our own story?" Dobson rephrased the question: "How odd is it that geographers can't excite the public about geography, yet others do so routinely?" That's an interesting question, but I was even more interested in what Dobson said next.

1491," Dobson continued, "and you'll find the 'stealth discipline,' geography, operating beneath the public radar. From Carl Sauer on, geographers led the way toward new understandings of the ancient Americas...Profound ideas reported in geographical literature and widely accepted by geographers did not reach broad public awareness for half a century or more, and then not directly from geographers themselves but from the able pen of science journalist Mann."

This is an interesting dilemma for geographers. Even more interesting to me is the idea that geographers like Carl Sauer and William Denevan were leading the revision of American history more than fifty years ago: Sauer in the 1930s and Denevan in the early 1960s. Historians only caught up when Alfred Crosby started writing about these issues in the 1970s, and Crosby couldn't find an academic publisher willing to touch
The Columbian Exchange. So as a historian, I think I've got even more claim to Gade's question. What's wrong with us?

Most of the geographers' criticism in the forum consisted of complaints that Mann hadn't spent enough time and effort covering the particular specialties of the reviewers. There's not a lot of "you got this wrong." More "why didn't you say more about this?" or "maybe by simplifying and dramatizing this point, you didn't do justice to the complexity of the issue." Those are fair criticisms, and Mann responds to them gracefully. It's great that geographers spent a lot of time thinking and talking amongst themselves about Mann's work and the relationship between scholarship and public understanding of their field. It’s a bit disconcerting that historians didn't.

I trolled JSTOR pretty extensively, hoping to find reviews of 1491 in history journals or the transcripts of similar panel discussions. Without much luck. I did find a review article by Colin Calloway in the January 2007 issue of
Ethnohistory, covering both 1491 and Julian Granberry's 2005 academic monograph, The Americas That Might Have Been. Calloway, who has written extensively on Native American History, had good things to say about 1491. The most interesting to me, though, was this: "Specialists will learn nothing new about their own areas of expertise…and ethnohistorians who have spent their lives dealing with the issues it covers may wonder what all the fuss is about." To be fair, Calloway explains what all the fuss is about and concludes by saying "The fact such a book is getting a lot of attention is surely a good sign." But still, I think he makes an important point.

The basic question in
1491, that Mann keeps returning to, is why do high school textbooks still mislead students about early American History? After all that geographers have uncovered and written about the pre-Columbian Western Hemisphere, why have historians not revised their stories? How have we managed to drop the ball so completely?

Things I learned from 1491


Okay, I'm a grad student, not a tenure-track EnvHist professor. So maybe it's easier for me to admit this. I learned stuff from Charles C. Mann's 1491.

Yep, in spite of doing a PhD teaching field in Global Environmental History. In spite of teaching American EnvHist several times. Mann covered things in 1491 I had not heard of, and other things I had heard of but hadn't dug deeply enough into. So I'm going through the book again with a fine-tooth comb, looking for things I ought to add to my course, study up on, or read his sources. And while I'm doing that, I'm going to try to pay careful attention to the organization of the book, the language, how Mann presents his material. All the things that, along with choosing interesting material in the first place, made the book a national bestseller.

First thing I noticed, as I reopened this book, was that Mann says he has been thinking about these topics for over two decades. It shows. In addition to 385 pages of text, my paperback edition includes over 150 pages of appendices, endnotes, bibliography, and index. In comparison,
Down to Earth has 295 pages of text, 71 pages of back matter. McNeill's An Environmental History of the Twentieth-Century World has 362 pages of text and about 50 pages of back matter, although its footnotes are at the bottoms of pages. More important, there's a lot of overlap between Mann's sources for his popular history and the academics' citations in their textbooks. And actually, there's material in Mann's story and sources that I haven't seen before -- possibly because it comes from outside the silo of academic History.

When I talk about American EnvHist, I like to start about 80 thousand years ago, when the
Homo sapiens who were our ancestors left Africa. So I loved the whole premise of Mann's book: that there was a lot going on in the Americas before Columbus's arrival and we should know about it. I immediately related to Mann's introductory attack on the Pristine Myth, and I appreciated the way he added urgency and suspense by contrasting the revisionists and the people (like Holmberg) whose work they were revising. Even so, I was unaware of William Denevan's discoveries in the Beni region of Bolivia, or of the efforts of people like Denevan and Henry Dobyns, who have been arguing these points since the 1960s. I'm still going to talk about Alfred Crosby in my class -- but I'm going to start mentioning these geographers too!

And yes, there's something to be learned about language and tone. I don't think any academic would have named a chapter "Holmberg's Mistake" or observed that "it was as if he had come across refugees from a Nazi concentration camp and concluded that they belonged to a culture that had always been barefoot and starving" (10). People have criticized Mann for dwelling too much on conflicts -- or even of trying to create them where they didn't really exist. But there are social and political consequences to the question of how many people were in the Americas before Europeans and what their lives were like. I often wonder if the critics of "confrontation" wouldn't prefer to go back to a time when we just didn't have to worry about these issues.

Another of the very effective elements of
1491 is that Mann has traveled to a lot of the places he describes and met a lot of the people whose work he cites. The personal observations Mann makes, the hardships, and even the trivial incidents of travel bring us into the story. Suddenly we're reading a narrative of discovery rather than a historiography. But my exercise today is combing through the book for material to add to my course. So what specifically am I going to add, that I hadn't covered before reading 1491?

The Beni region, because I think it's interesting and compelling that things are still being discovered.

"Gaspar Corte-Real abducted fifty-odd Indians from Maine [in 1501]. Examining the captives, Corte-Real found to his astonishment that two were wearing items from Venice: a broken sword and two silver rings" (47). I'm going to try to put more stress on the idea that Whites and Indians interacted in a wider variety of ways. Especially in New England in the century
before the 1616-17 epidemic and the beginning of English colonization.

The depopulation of the territory first explored by Hernando De Soto in 1539 and revisited in 1682 by La Salle, who found the land "deserted--the French didn't see an Indian village for two hundred miles" (108).

The section on challenges to Clovis chronology is excellent, but I'm already covering that. And since the book came out, there have been genetic discoveries that fill out the story of Kennewick Man (and "Hoyo Negro Girl") which I'm already planning to add.

Aspero and Caral, in the Norte Chico. If Aspero is actually in the running for the world's oldest city, this is probably worth mentioning (201-9).

I might assign the passage (212-24) on Maize. It includes a description of how many varieties are still eaten in Mexico, and introduces the concept of landraces, which would be useful because the idea comes up again later in the semester.

I might also assign Chapter 9, "Amazonia," (315-49). It introduces the idea that the Amazon region may have been much more heavily populated in the past, discusses agro-forestry, and covers another controversy. This one is interesting, because part of the argument seems to be over present use of the Amazon. Opponents of the idea that a lot of people have been able to support themselves in the region claim that accepting that conclusion would open the doors to further deforestation and development. Despite the fact that the evidence suggests the people who thrived there in the past did so by tending the trees! So obviously, this could lead to an interesting discussion in a class.

Finally, Mann's suggestion that the die-off of most of the Americas' Indians caused other animal populations to boom is probably worth mentioning. Especially since (like many people, I imagine) I already mention the extinction of the passenger pigeon and quote American authors' descriptions of the flocks that took days to pass by. Another opportunity to talk about dynamic systems being more accurate descriptions of the world than steady states.