The widespread exchange of plants, animals, and diseases between the Old and New Worlds is called the Columbian Exchange.
The term describes the biological and ecological transfers that accelerated after Christopher Columbus’s 1492 voyage and the European colonization of the Americas. The Old World generally refers to Afro-Eurasia, while the New World refers primarily to the Americas. Some transfers were deliberate, such as transporting crops and livestock; others were unintended, especially the spread of infectious diseases.
American crops including maize, potatoes, tomatoes, cassava, cacao, tobacco, and chili peppers traveled to Europe, Africa, and Asia. Europeans brought wheat, rice, sugarcane, cattle, horses, pigs, sheep, and chickens to the Americas. These introductions transformed diets, agriculture, transportation, and economies around the world.
The exchange also had devastating consequences. Smallpox, measles, influenza, and other Old World diseases reached Indigenous American populations that lacked previous exposure and immunity. Historians therefore use the term for a process that produced both major global changes in food and commerce and catastrophic demographic losses. Historian Alfred W. Crosby popularized the name in his 1972 book.