All of these plants are originally from North or South America. The exchange of plants, animals, and diseases between the "new" and "old" worlds that happened beginning in the late 1400s is known as the Columbian Exchange. None of these plants existed in Europe, Africa, Asia, or Australia prior to then.
yes, that includes popcorn, which believe it or not, does grow on a cob
no Irish potato famine without these bad boys. also, imagine potato-less pierogi's!?