The plague stopped the movement plus lack of technology
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All along<span> the the </span>west<span> and </span>south<span> coasts of </span>South America<span>, the </span>Andes<span> are a barrier to movement in interior. As a result, more </span>settlement<span> in </span>South America<span> has occurred </span>along<span> the eastern and northern coasts.</span>