In the early 1990s, the North American Free Trade Agreement (NAFTA)—the concrete embodiment of globalization in North America—had the unanticipated consequence of catalyzing labor transnationalism among key Mexican, United States, and Canadian unions and union federations. I argue that NAFTA stimulated transnationalism by creating two institutional fields—transnational trade-negotiating and legal fields—that provided new arenas for workers to build collective interests, strategies, and trust. In this chapter, I revisit these issues by examining whether transnational ties have been relevant to the negotiation and/or enforcement of the United States-Mexico-Canada Agreement (USMCA), which replaced NAFTA when it entered into force on July 1, 2020. I show that labor transnationalism continues to be an important factor in efforts to strengthen labor rights and improve working conditions across North America, even though some relationships waned as NAFTA’s labor side agreement proved ineffective in this effort.