Sic transit: Alfred Crosby's Intellectual Legacy

I was sorry to hear of the recent death of Alfred Crosby (1931-2018), professor emeritus at the University of Texas and one of the more influential historians of the past half-century. Crosby’s principal claim to fame was his authorship of The Columbian Exchange (1972), a study of the transfer of organisms between the Eastern and Western Hemispheres that became a foundational text in colonial and environmental history. Crosby’s book was so far ahead of its time that he could not find a university press willing to publish it and had to sign with Greenwood, an obscure independent academic publisher. Greenwood and Crosby had the last laugh, as Columbian Exchange went on to sell more than 80,000 copies (about 100 times as many as the typical academic book) in the next quarter-century.

Crosby observed that the word “exchange” in his title misled readers somewhat. Most of the biological transfers he studied ran in one direction, from the Old World to the New. Europeans introduced to the Americans new plants, like wheat and peaches and Kentucky bluegrass; new animal species, like pigs and horses and cows (all of which flourished); tens of millions of human beings, most of whom, prior to 1860, came involuntarily from Africa; and new diseases like smallpox and typhoid, which reduced the indigenous American population by more than eighty percent. In three of these categories little flowed back to the Old World. Only two or three thousand Native Americans voyaged to Europe before 1800, almost no American animals adapted to Eurasian or African environments (apart from a few small mammals like the raccoon), and no American diseases, except possibly syphilis (and Crosby expressed skepticism about its alleged American origin), crossed the Atlantic from west to east. Plants proved the great exception: Eurasians and Africans slowly but steadily adopted high-yield American food crops like maize, potatoes, and cassava, along with such piquant or addictive newcomers as cacao, tobacco, tomatoes, and chilis. American cultivars increased the total food supply of Eurasia and helped sustain high population growth there,* even as the Native American population plummeted. Columbus and his successors set off not only a major biological exchange but a global demographic revolution.

Crosby followed up this seminal publication with two more works that Native Americanists and colonialists found (I think) equally important. "Virgin Soil Epidemics as a Factor in the Aboriginal Depopulation in America" (1976) asked why Eurasian diseases hit Native Americans with such ferocity, and found an answer in social dynamics. A "virgin-soil" illness, hitting a population with zero acquired immunity, sickens the entire community or region at once, leaving no-one well enough to take care of the sick. Hunger, dehydration, and cold kill many who would otherwise have a fighting chance at recovery. Ecological Imperialism (1986) extended Crosby's observation about the imbalanced character of the Columbian Exchange. In this later book he argued that the success of European colonial ventures in the "Neo-Europes," the high-latitude settler-colonial societies like Australia and the United States, depended chiefly on the organisms that the colonists brought with them, their "portmanteau biota" of livestock, weeds, and pathogens. European imperialism owed its conquests to biology, not technology or culture.**

Alfred Crosby continued publishing into his seventies. His last three books studied quantitative knowledge, projectile weapons, and energy technology, discussing these highly-technical subjects in clear, crisp, often witty prose. That he kept his mind and his writing sharp during the onset of Parkinson's Disease showed a grace and endurance most of us can only hope to attain. For my part, I will account myself very successful indeed if I can write a book even one-tenth as influential as Columbian Exchange. And I am sorry I never had a chance to meet the maestro in person.

* Europe's population doubled and China's population tripled between 1650 and 1800. 

** Ecological Imperialism won an audience outside of History departments and well beyond the academy. I first heard of the book during a panel on world-building at the 1989 World Science Fiction Convention.