“On (Our) American Ground” traces the relevant genealogies, and itineraries, of a song and a site whose various symbolic and practical constructions have helped to determine what a transnational American historical past can allow us to imagine of a postnational American future. The song “Guantanamera” is a quasi-officially Cuban cultural and national artifact, though in fact its history of composition, performance, and recording reveals it to be a remarkably unstable and fluid text. The site, the U.S. naval base on Guantánamo Bay, Cuba, continues into 2007 to challenge political and legal theorists to worry the limits of what is politically thinkable and doable. Together, these two decidedly “local” institutions have historically drawn into themselves an impressive procession of political and cultural figures (from José Martí to Celia Cruz to Wyclef Jean), a procession that has collectively embodied, and performed, the complex careers of the nation, the transnation, and the postnation through their engagements of the matter of Guantánamo/“Guantanamera.” The piece then implicates in that procession populations that bear no simple relationship with any of the more available categories (national, racial, cultural) according to whose terms we conventionally organize ourselves and others. The piece concludes by suggesting what new forms of knowledge can come out of a critically engaged, “postnational” American studies, and in turn out of a “postnational” Latino studies, a still-emerging disciplinary field that understands its own organizing category as strategically historical, contextual, and critical.