This dissertation reveals how religious factors affected the development of the Korean War. Much prior research has analyzed the causes and nature of the Korean War, in part because of the war’s impact upon later events, from the Cold War to the present-day geopolitical standoff. Though the war has been much-studied, religious factors have rarely been included in these analyses. This de-emphasis of religion may be a justifiable simplification in general war historiographies, but not in the specific case of Korea. This current study uncovers the unique role of religion in Korean-American relations and in Korean culture and politics, prior-to-and-during the time of the Korean War.