For more on the crops that sustained settlers and where they were grown, see T.E.D.'s answer on another related question herehere. Note he refers to indigenous peoples being removed from temperate areas for farming land - one of the reasons you don't have large indigenous populations in temperate countries like the United States or Argentina, both of which received the largest influx of immigrants and both of which conquered and removed indigenous people. Note that Argentina has a larger GDP per capita than most Latin American countries, and has historically been somewhat more stable.
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