What was the Columbian exchange? What was exchanged between Europeans and Indians?

When Europeans and Indians came into contact, they immediately began to trade knowledge, tools, crops, and other items. One historian has called this process the Columbian exchange, because it followed in the wake of Columbus' voyages to the Western hemisphere and his return to Europe. Europeans gained much in this exchange (remember that Columbus was seeking a route to Asia and India to aid the spice trade.) Europeans' diet was greatly enriched by the addition of plants native to the Western hemisphere, such as potatoes, beans, tomatoes, and chocolate. Europeans later gained tobacco.

Indians also gained some new items from their encounter with Europeans. Indians' lives were greatly changed by the introduction of horses, cattle, and other livestock. Those Indian peoples who became skilled horsemen gained great geographic mobility, often at the expense of their Indian neighbors. Explorers introduced Indians to metal tools (especially knives and pans), cloth, firearms, and alcohol