The Columbian Exchange

Two worlds, one ocean

For thousands of years, the Americas and the Eastern Hemisphere (Europe, Africa and Asia) had separate plants, animals and diseases. After Christopher Columbus crossed the Atlantic in 1492, ships began crossing regularly, and they carried living things in both directions. In his 1972 book, historian Alfred W. Crosby gave this swap a name: the Columbian Exchange.

From the Americas to the world

Indigenous farmers in the Americas had developed corn (maize), potatoes, tomatoes, cacao (the bean chocolate comes from) and chili peppers. All of them crossed the ocean. Potatoes grew well in cool climates and, mostly in the 1700s and 1800s, helped feed Europe's growing cities. Tomatoes reached Europe in the 1500s, but Italians were slow to eat them; the first printed Italian tomato sauce recipe dates to 1692. Today it's hard to picture Italian food without them.

From Europe, Africa and Asia to the Americas

The other direction brought wheat, sugar cane, cattle, pigs and horses. Horses had lived in North America long ago but died out about 10,000 years ago; the Spanish brought them back. Horses spread north from Spanish New Mexico, especially after the Pueblo Revolt of 1680. By the early 1700s, Plains nations like the Comanche had built a new way of life on horseback, for travel, hunting bison and trade.

The germs that crossed too

The exchange was not equal. Ships also carried diseases such as smallpox and measles. Indigenous peoples of the Americas had never been exposed to them, so they had no immunity, and epidemics killed millions. Far fewer diseases went the other way. Kitchens, farms and whole populations on both sides of the Atlantic changed forever.

Try it yourself

Look at the ingredients of one meal you ate today. Sort them into two lists: from the Americas (corn, potatoes, tomatoes, peppers, chocolate, beans, squash) and from Europe, Africa or Asia (wheat, rice, sugar, beef, pork, chicken). How many of your meals mix both?

Good to know

• Historian Alfred W. Crosby coined "Columbian Exchange" in his 1972 book.
• Tomatoes reached Europe in the 1500s; Italians were slow to eat them, and the first printed Italian tomato sauce recipe dates to 1692, which is why we say "eventually."
• The potato's big role in feeding Europe's population growth came mostly in the 1700s and 1800s.
• Horses lived in North America long ago but died out about 10,000 years ago; the Spanish reintroduced them.
• Horses spread north from Spanish New Mexico, especially after the Pueblo Revolt of 1680, and the Comanche had a horse-based way of life by the early 1700s.
• Sugar cane originated in Asia and came to the Americas by way of Europe's Atlantic islands; wheat and cattle came from Eurasia.
• Old World diseases (smallpox, measles, influenza) killed far more people than any disease that went the other way; the origin of syphilis is debated.
• The exchange also included the forced transport of millions of enslaved Africans to grow crops like sugar. Later episodes cover it.

For AP US History learners

This is AP US History Period 1 (1491-1607): know that the Columbian Exchange moved plants, animals and diseases between the hemispheres, changing diets and economies in Europe and devastating Indigenous populations in the Americas.