Alfred W. Crosby, Jr. was an American historian who was instrumental to the development of the field of environmental history. His work employs interdisciplinary approaches, drawing on the methods and findings of not only fellow historians but also of archeologists, anthropologists, biologists, and ecologists. The Columbian Exchange established this field of study in the early 1970s and paved the way for future historians to study the relationship between humans and their biological and ecological environments as they assess the social, political, cultural, and economic consequences of those interactions.

His next book, Ecological Imperialism: The Biological Expansion of Europe, 900-1900 (1986), focused on European colonization and imperialism in regions of the world beyond the North and South American continents. Both books provided explanations as to why Europeans were successful in their quests to establish powerful global empires that ushered in an era of inequality that continues to the present day. Though he acknowledges the significance of other factors such as technology in European conquest, he identifies environmental factors as the primary reasons for these empires’ triumph.

The US Civil Rights Movement in the 1960s inspired Crosby’s worldview and his work as a historian. He began to think globally. It also fostered his interest in the intersection between biology and history: “I fled from ideological interpretations of history and went in search of the basics, life and death” (xxi).