USA HISTORY

Detailed explanation-1: -In addition to North America’s Native American populations, the Mayan and Incan civilizations were also nearly wiped out by smallpox. And other European diseases, such as measles and mumps, also took substantial tolls – altogether reducing some indigenous populations in the new world by 90 percent or more.

Detailed explanation-2: -They had never experienced smallpox, measles or flu before, and the viruses tore through the continent, killing an estimated 90% of Native Americans. Smallpox is believed to have arrived in the Americas in 1520 on a Spanish ship sailing from Cuba, carried by an infected African slave.

Detailed explanation-3: -Earlier, the successful conquest of Mexican Aztec and Peruvian Inca empires by a handful of Spanish conquistadors led by Hernando Cortes and Francisco Pizarro, respectively, resulted in large part from epidemics of smallpox and measles virus infection that decimated the native defenders.

Detailed explanation-4: -In 1519 Hernán Cortés landed on the shores of what is now Mexico and what was then the Aztec Empire. In 1520 another group of Spanish arrived in Mexico from Hispaniola, bringing with them the smallpox which had already been ravaging that island for two years.