That all happened before the settlers arrived. The entire continent was in disarray before the settlers arrived. The first round of plagues happened right after the first Spanish explorers landed in Florida. It reached Hudson Bay withing two years. The history from the original settlers to today was completely skewed because what really happened has only recently come to light with the latest archaeological findings. Most of the wars fought were between invasion and the arrival of the settlers because, with 90% loss of life, most of the agrarian societies fell apart and were forced back to hunter/gatherer societies, causing territorial disputes that were not that prevalent before.
The first explorers encountered fairly sophisticated societies and communities that they mercilesly killed to steal whatever the Spanish considered treasure. Those who managed to survive the original onslaught, died of the diseases left behind. Most of what we think we know about the early history of occupation is false, maybe no intentionally so much as ignorance. Unless someone has been keeping up to date on the latest breakthroughs in archaeology and anthropology, chances are they are full on misconceptions and misinformation.
that is a good point. The Aztecs actually threw Cortez out until disease thinned their ranks by 85 % plus. then he came back to finish the job.
the Inca had a rudementary idea that the Whites were spreading Viral diseases. Pizarro was EXTREMELY lucky to arrive at the climax to their civil war, - and meet an arrogant, rather clueless young sun god.