This senior thesis studies the character and influence of a young American naval officer and diplomat. George Clayton Foulk, the 1st Naval Attaché to the United States Legation and the 2nd U.S. Minister to Korea, brought his intellectual ability and passion to this East Asian country. He hoped for Korea to become an independent, modernized state. Due to the strong Chinese opposition and lack of assistance from the U.S. government, Foulk failed to realize his dream and left Korea in disgrace. However, his service instilled a positive image of America in the minds of many Koreans. By closely examining his letters and journals, this thesis brings an image of a cosmopolitan who expressed genuine understanding of and sympathy for Korea. More importantly, this thesis introduces his vision that America must become an exceptional country which spreads its values across the world through peaceful means. Even today, the clash between Foulk’s idealism and the realpolitik of Washington policymakers raises a question on the future of American diplomacy.