What exchanges developed in the Atlantic World after European contact and how did they begin to shape the Americas?

the Columbian Exchange

Christopher Columbus introduced horses, sugar plants, and disease to the New World, while facilitating the introduction of New World commodities like sugar, tobacco, chocolate, and potatoes to the Old World. The process by which commodities, people, and diseases crossed the Atlantic is known as the Columbian Exchange.

  b.

there are isolated pockets of farming, generally around rivers and oases, which are used for irrigation.

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