USA HISTORY

Detailed explanation-1: -When the Europeans arrived, carrying germs which thrived in dense, semi-urban populations, the indigenous people of the Americas were effectively doomed. They had never experienced smallpox, measles or flu before, and the viruses tore through the continent, killing an estimated 90% of Native Americans.

Detailed explanation-2: -Indigenous people both north and south were displaced, died of disease, and were killed by Europeans through slavery, rape, and war. In 1491, about 145 million people lived in the western hemisphere. By 1691, the population of indigenous Americans had declined by 90–95 percent, or by around 130 million people.

Detailed explanation-3: -Diseases such as treponemiasis and tuberculosis were already present in the New World, along with diseases such as tularemia, giardia, rabies, amebic dysentery, hepatitis, herpes, pertussis, and poliomyelitis, although the prevalence of almost all of these was probably low in any given group.

Detailed explanation-4: -Smallpox was the disease brought by Europeans that was most destructive to the Native Americans, both in terms of morbidity and mortality. The first well-documented smallpox epidemic in the Americas began in Hispaniola in late 1518 and soon spread to Mexico.