Alfred W. Crosby Jr. was Professor Emeritus of History, Geography, and American Studies at the University of Texas at Austin, Harvard University and University of Helsinki.

Crosby studied at Harvard University and Boston University. He was an inter-disciplinary researcher who combined the fields of history, geography, biology and medicine. Recognizing the majority of modern-day wealth is located in Europe and the Neo-Europes, Crosby set out to investigate what historical causes are behind the disparity, investigating the biological factors that contributed to the success of Europeans in their quest to conquer the world. One of the important themes of his work was how epidemics affected the history of mankind.

As early as the 1970s, he was able to understand the impact of the 1918 flu pandemic on world history. According to Hal Rothman, a Professor of History at the University of Nevada, Las Vegas, Crosby “added biology to the process of human exploration, coming up with explanations for events as diverse as Cortés’ conquest of Mexico and the fall of the Inca empire that made vital use of the physical essence of humanity. In 1972 he created the term "Columbian Exchange" in his book of the same name. The term has become popular among historians and journalists, such as Charles C. Mann, whose 2011 book 1493: Uncovering the New World Columbus Created expands and updates Crosby's original work. Crosby was also interested in the history of science and technology.

He wrote several books on this subject, dealing with the history of quantification, of projectile technology, and the history of the use of energy. He said that the study of history also made him a researcher of the future. He was very much interested in how humankind could make the future a better one. He has taught at Washington State University, Yale University, the Alexander Turnbull Library in New Zealand, and twice at the University of Helsinki as a Fulbright Bicentennial Professor, most recently in 1997–98. He was appointed an academician by Finnish president Martti Ahtisaari. He retired from the chair of Professor Emeritus of History, Geography, and American Studies of the University of Texas at Austin in 1999. Crosby’s hobbies included birdwatching and jazz, on which topic he could lecture with great expertise. He was married to linguist Frances Karttunen.