What large- scale changes happened to the populations of the Americas?

Um well north korea is a very harsh place because students go to school for 24 hours and almost never rest and the president is well i think sends to much bomb that’s what i think

Be the economy is horrible so people immigrate to the usa for a better life. most people just grow up from poverty and work day and night to support their family, some just come because there is a lot of drug dealers and gang that assaults people.