This dissertation is about the first American "missionary" to Korea, Horace N. Allen (1858-1932). I show that America's interests in both expansionism and missions provided Allen the opportunities to be involved in Korea and Hawaii. Had the U.S. focused on only either expansionism or missions, Allen would not have had the same efficacy regarding concessions, the development of Christianity, and the illegal transfer of Korean laborers to Hawaii. Two scholars have used the Allen MSS in their research. Fred Harrington focuses on Allen's endeavors in Korea and Wayne Patterson focuses on Allen's endeavors in Hawaii. However, I believe that Allen's involvements in Korea and Hawaii were connected by expansionism and missions. I show that Allen's activities in Korea and Hawaii were related by using the following primary sources: (1) The Allen MSS; (2) official U.S. Documents; (3) two Korean contemporaries of Allen who immigrated to Hawaii and wrote English documentations (Soon Hyun and Easurk Chaff); (4) monographs by a select group of missionaries who were Allen's contemporaries; and, (5) various news clippings that covered Allen's tenure in Korea. Due to the limitations of this project, the bulk of my research will center on sources 1-3.