North America has been the site for three successive protest cycles revolving around the politics of international trade over the past four decades, including the Canada–United States Trade Agreement (CUSFTA), the North American Free Trade Agreement (NAFTA), and most recently the United States–Mexico–Canada Agreement (USMCA). This chapter analyzes transnational activism that challenged the USMCA, documenting ways that activists carved out space for different forms of cross-border advocacy and collaboration in this third North American trade protest cycle. Applying concepts from Tarrow’s “new transnational activism,” two main arguments are advanced: (1) that actors from Canada, the United States, and the Mexico did not stand helplessly by while the USMCA was negotiated and implemented, but rather engaged in protest to secure more favorable outcomes in interactions with state authorities (material, symbolic, and/or emotional); and (2) that the organizations and groups involved demonstrated social resilience in an age of insecurity and neoliberal crisis, sustaining and advancing their well-being in the face of challenges to their economic or symbolic status through transnational activism.