The export product that eclipsed silver and generated significant prosperity (for the "decent people" at least) for Peru during the middle of the 19th century was:

The answer is guano

Explanation:

The export of the product known as guano generated more revenue for the people of the South American country of Peru in the middle of the 19th century. The export of this product to other part of the world was further boosted by the quality of the leadership of the country at that time, because of the charismatic ability and the style of leadership of their president known as Ramon castila the people were given the needed support required to produce the product. The production of this guano and eventual export to other parts of the world led to the improvement in the quality of life's of the people of the country by bringing them out of poverty to significant prosperity.

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