You always hear about how small pox and other diseases decimated Native American populations because they had no resilience to it, how come the Europeans were never affected by a disease transmitted to them by the Native Americans? Was there simply not a similarly devastating disease native to just North America?
Actually, Europeans did suffer quite a bit from the diseases of North America. I wrote a short answer to this question here: https://www.reddit.com/r/history/comments/73piad/comment/dnt8yaf
Regions like the Chesapeake were just ripe with malaria, for instance, and it took extensive land reclamation and the constant influx of new arrivals to overcome the population losses. The more south you went, the worse it was: the Caribbean and those lovely tropical destinations we think of were considered 'grave yard shifts,' with emphasis on the grave yard. After several populations, immunity is built up through survivors, but by no means were Europeans immune in the slightest. The books I list in that link have many examples of children being orphaned and forced to raise themselves/maintain the family farm as they'd lose both parents early to disease.
To quote myself there, "The Chesapeake colony , began in the early 1600s, wasn't self-sustaining until the 1690s due to the high deathrate." Constant arrival of new settlers and the gradual conversion of mosquito harbouring wetlands into farmland, with local immunity built up by the survivors or from techniques learned from the local indigenous, allowed the European colonies to grow. And once they did start to grow, it was an explosion of people.