The impact of these Eurasian diseases on Native Americans was one of human history’s most abrupt and severe population disasters. Even the Black Death did not kill as large a percentage of Europeans, and when diseases recurred in Europe, they generally killed their victims over a much longer time-span due to the inherited immunity of European populations. American native populations had no inherited immunities and disease spread virulently. For example, there were over a million people living on the Caribbean island of Hispaniola in 1492 when Columbus left his 39 sailors in La Navidad. By 1548, there were only 500 natives left alive. A million people had disappeared in a little over 50 years. ![[Smallpox_virus_virions_TEM_PHIL_1849.jpg]] *Smallpox virus* The populations of other Caribbean islands like Cuba were similarly wiped out. Whole societies disappeared, and this was not only a tragedy for the cultures that vanished. The reduction of native populations began a cycle of violence that became central to the history of the Americas. Once there were no natives left to work on European sugar plantations, enslaved Africans—who had a similar acquired immunity as Europeans—were considered crucial to the survival of the West Indies sugar economy. ![[2560px-Marché_aux_Negres_by_Johann_Moritz_Rugendas_2.jpg]] *A slave market in Brazil* The greater population densities of Central and South America enabled contagious diseases to spread more quickly there. Heavily-traveled roads in central Mexico actually helped spread disease beyond  areas that had been reached by Spanish explorers. Cities were wiped out that had not yet even seen a white man. The population of the Aztec heartland dropped from about 25 million on the eve of the Spanish conquest in 1519 to just under 17 million a decade later. One out of every three native people died in just ten years. After another decade the Aztec population was reduced to about 6 million. Three out of four people in the Aztec world disappeared in 20 years. Imagine writing a list of your 10 closest friends and family, and then randomly crossing off seven names. By 1580, the Aztec world had been hollowed out to less than 2 million people, from a starting point of 25 million. Cross off two more — you’re down to one friend. ----- Next: [[4.16 - Black Legend]] Back: [[4.14 - Columbian Exchange]]