The Great Exchange The economic interactions that took place when people from different continents met changed the world forever. The Columbian Exchange is the name given to the huge exchange - some good, and some terrible- of plants, animals foods, humans, diseases, and ideas that began after Columbus arrived in 1492. Many of these exchanges were good. When explorers brought the potato back to Europe from America it became a food staple in Europe. In the Americas, European cows gave milk and European chickens laid eggs - new, easily-raised protein sources that did not have to be hunted first. Plagues and Poxes A Human Exchange One exchange was terrible. The worst result of the Columbian Exchange was the spread of diseases from Europe to the Americas. At first the spread of plague was simply a tragic accident, but in time, some explorers deliberately infected Indian villages in order to claim territories for their kings and queens. The climate in large areas of the Americas, especially the Caribbean and South America , was perfect for the growing of sugar cane. Huge sugar plantations spread across the islands of the Caribbean, and with them, the need for more workers. At first the Spanish made the Indians slaves. In 1542, the Spanish government forbade making slaves of the Indians. A new exchange began - the taking by force, of millions of people from Africa to toil in America's fields.