USA HISTORY

Detailed explanation-1: -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.

Detailed explanation-2: -Scholars Nunn and Qian estimate that 80–95 percent of the Native American population died in epidemics within the first 100–150 years following 1492. The deadliest Old World diseases in the Americas were smallpox, measles, whooping cough, chicken pox, bubonic plague, typhus, and malaria.

Detailed explanation-3: -Smallpox arrived on Hispaniola by 1519 and soon spread to mainland Central America and beyond. Along with measles, influenza, chickenpox, bubonic plague, typhus, scarlet fever, pneumonia and malaria, smallpox spelled disaster for Native Americans, who lacked immunity to such diseases.