Proper noun
the Columbian Exchange (uncountable)
The widespread transfer of animals, plants, culture, human populations, communicable diseases, technology and ideas between the American and Afro-Eurasian hemispheres in the 15th and 16th centuries, related to European colonization and trade after Christopher Columbus' 1492 voyage.
Columbian exchange
Alternative letter-case form of Columbian Exchange
Alfred W. Crosby, The Columbian Exchange, Westport, 1972, pp. 39, 45,47. Source: Internet
Barnston is describing a trade that forms part of what is called the Columbian Exchange. Source: Internet