For generations of North and South Koreans, the 1905 Taft-Katsura Memorandum or “secret treaty” has been emblematic of the US decision to support the Japanese annexation of Korea around the turn of the twentieth century. While scholars have periodically raised objections to the popular tropes of a backroom treaty that dictated the fate of Korea, these have had little impact on how the Taft-Katsura Memorandum has been imagined by many Koreans. In the case of North Korea, the Memorandum is yet another evidence of American perfidy which justifies the need for constant vigilance and avoidance of undue dependence on any outside power. In South Korea, the dominant narrative of the Taft-Katsura Memorandum is not one of America living up to its evil reputation, but of America falling short of its good ideals. In the case of both North and South Korea, depictions of the Taft-Katsura Memorandum in textbooks, popular comic book histories, and political editorials probably exert far more influence on how this document is remembered and understood than do a dozen scholarly articles on the subject. The persistence of the idea of a Taft-Katsura “secret treaty” in narratives of modern Korean history illustrates the tension between actuality, scholarly history, and popular memory.