There is a growing scholarly consensus that Latin American regionalism has entered a new phase. For some observers, the increasing complexity of regional cooperation initiatives renders collective action ineffective. For others, the creation of new schemes signals a “posthegemonic” moment that has opened a space for collaboration on social issues. Both camps attribute this shift to the absence of the United States and the presence of left-leaning governments. By contrast, this study demonstrates that this agenda is not new, nor has the United States impeded similar initiatives in the past. In fact, the United States was instrumental in expanding regional cooperation on social issues in the early twentieth century. Instead, this article argues that agenda shifts are best explained by an evolving consensus about the role of the state. The “new agenda” is in line with historical attempts by governments to use regionalism to bolster their own domestic reforms.