Over the past two decades, human trafficking has come to be seen as a growing threat, and transnational advocacy networks opposed to human trafficking have succeeded in establishing trafficking as a pressing political problem. The meaning of human trafficking, however, remains an object of significant–and heated–contestation among transnational actors with opposing perspectives on prostitution, the appropriate balance between law enforcement and human rights protection, and migration. The outcomes of disputes over meaning are highly significant. Anti-trafficking discourses establish regimes of knowledge that set boundaries for how scholars, activists, legislators, and citizens conceive of human trafficking–they establish what trafficking is and who counts as trafficked, and create narratives that explain how trafficking has become a problem and what should be done to fix it. In this dissertation I conduct a genealogical discourse analysis of anti-trafficking advocacy, policy, and scholarship in the United States from the late 1970s to 2000, looking in particular at feminist and religious abolitionist advocacy networks, and the role they play in the creation of the U.S. Trafficking Victims Protection Act of 2000. I argue that “human trafficking” is better understood as a contested concept rather than as an objectively given problem. The meaning of trafficking is constructed rather than inherent, and inseparable from the political context through which it is produced.