The Columbian Exchange

The Columbian Exchange is the movement of living things — plants, animals, and pathogens — and of people between the Old World and the New after Columbus’s voyages reconnected hemispheres that had developed separately for thousands of years. It was not a fair trade: some exchanges brought abundance, others catastrophe, and their effects fell very unevenly.

Before 1492, the Americas and the Eastern Hemisphere had very different inventories of life. The Americas had few domesticated animals — dogs, llamas, guinea pigs, and a few fowl — and no wild horses or cattle to tame. The Old World had many herd animals, which, as Crosby explains, were among humanity’s richest sources of disease microorganisms. Because people in the Old World had long lived in dense populations alongside livestock, they carried diseases — smallpox, measles, malaria, yellow fever, typhoid, cholera, plague — to which Native Americans had no acquired immunity.

The result was a demographic disaster. Epidemics often spread ahead of European settlers themselves, as in coastal New England, where diseases spread by earlier English visitors devastated the Wampanoag before the Pilgrims landed at Plymouth. Population collapse made conquest and colonization far easier and helped drive Europeans to import enslaved Africans as laborers.

• New foods for the world. American crops — maize, potatoes, manioc, peanuts — became staples in Europe, Africa, and Asia, supporting population growth across the globe.
• Sugar and slavery. Sugar cane, brought to the Caribbean and Brazil, created plantation economies built on the labor of enslaved Africans.
• Tobacco. An American plant became the cash crop of colonial Virginia after 1612 and a global commodity.