... frustrations with how independence had led to situations where caudillos (authoritarian leaders) rose to power.
Bolivar had wanted a united Spanish America, a great nations, but the wars of independence had tended to result in charismatic military rulers leading their own countries in authoritarian ways -- what we today would call dictators.
<span>"to attract the Confederate States to Join the Union" would be your answer
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Can you explain a bit more in detail?