 As Secretary of State , Blaine was a transitional figure , marking the end of an isolationist era in foreign policy and foreshadowing the rise of the American Century that would begin with the Spanish – American War . His efforts at expanding the United States ' trade and influence began the shift to a more active American foreign policy . Blaine was a pioneer of tariff reciprocity and urged greater involvement in Latin American affairs . An expansionist , Blaine 's policies would lead in less than a decade to the establishment of the United States ' acquisition of Pacific colonies and dominance of the Caribbean . 
