Final answer:
Native American tribes were highly susceptible to European diseases due to a lack of prior exposure and immunity, leading to high mortality rates. Contributing factors included malnutrition and the rapid spread of infection in densely populated areas. Historians debate whether the introduction of these diseases was intentional or an unintended consequence of European settlement.
Step-by-step explanation:
Native American tribes were highly susceptible to diseases introduced by European settlers primarily because they had no immunity to these new illnesses. The diseases, such as smallpox, measles, and influenza, originated from Europeans and their domesticated animals, to which the native populations had never been exposed. The situation was exacerbated by factors such as malnutrition due to the destruction of crops by European livestock and social disruption, which weakened the indigenous peoples' immune systems. Furthermore, the dense populations in settled regions allowed infections to spread rapidly, leading to devastating mortality rates that could reach as high as 95 percent among native communities.
The introduction of diseases like smallpox was particularly catastrophic. This, combined with forced removals, slavery, and war, led to a historical decline in Native American populations. However, the extent to which the spread of diseases was planned by European colonizers remains a contentious issue among historians. Some diseases were so lethal that the Native American population on Hispaniola plummeted from over a million in 1492 to merely 500 by the year 1548.