Abstract Newspapers were the primary literary institutions of Latinx modernism, and attending more centrally to newspaper and other periodical literature changes the way we understand Latinx literary history. It demonstrates not only the generic and formal dynamism of Latinx writing but also how thoroughly embedded that writing has always been in hemispheric currents of thought and textual circulation. In this essay, I give an account of how Latinx modernism contributes to and transforms the fields of Latinx literature, modernist studies, and Latin American studies. I describe the print-cultural archive of Latinx modernism and justify my use of the term Latinx based on the transnational identifications of newspaper literature pages during this period. I then outline the problems and potentiality presented by the Latinity of Latinx writing, building on the work of Latin American decolonial theorists. Relying on examples from the archive, I show how Latinx modernism engages what I am calling the spirit of Latinoamericanismo and in the process transforms our conception of American modernity, showing it to be inextricable from coloniality. The spirit of Latinoamericanismo figures the oppositional potential of Latinx modernist literature, including its contradictions and limits.