The emergence of right-wing populism in transatlantic democracies is one of the most significant political trends of the 21st century. When then-candidate Trump denounced globalist policies and elites in his 2016 Presidential campaign, he introduced the American public to a new term: ‘globalism’. Since then, anti-globalist populism has become the definitive political ideology of the Republican Party and right-wing movements around the world. Where did anti-globalist populism come from? To answer this question, this dissertation explores the previously neglected history of anti-globalist ideology and politics in the United States from 1945 to 2000. I argue that the historical emergence of anti-globalism as a distinctive ideology in the late 20th century U.S. can be attributed to the long-term efforts of two far-right groups: the John Birch Society and the Liberty Lobby. These organizations were established in the late 1950s by far-right social movement leaders seeking to promote a far-right conspiracist ideology oriented against Communism and internationalism. During the 1960s, 1970s, and 1980s, these organizations institutionalized into the ideological and organizational hubs of the American far right. After multiple decades, these groups produced a ‘conspiracist canon’ of anti-globalist books and newsletters that were among the most widely read and circulated texts on the American Right. By the 1990s, many conservatives were already thinking through the ideological lens of anti-globalism. During the 1990s, a backlash against globalization took place on the American Right. Republican politicians, anti-government militias, and violent extremists were all united by their shared opposition to an ambiguous ‘New World Order’. I argue that anti-globalist ideology pre existed the hyper-globalization that began in the 1990s. By tracing the history of anti-globalism before globalization, this dissertation offers a novel argument about the origins of contemporary populism and the history of the American Right.