Nineteenth-century American literature has always been part of the conversations that now comprise contemporary approaches to the field of western literary studies, specifically “critical regionalism” and the “New Western Criticism.” The very issues at the heart of critical regionalist approaches—such as hybrid identities, third-spaces, contact zones, and the relationship between the local and the global—were anticipated in and by the literature of the nineteenth century. This claim comes into better view when nineteenth-century American literature is conceptualized through the US-Mexican War rather than the US Civil War. Defining the literary history of the United States through its hemispheric and international, rather than its internal and domestic, boundaries encourages the comparative practices and transnational methodologies called for by critical regionalist approaches. This conceptual remapping can lead scholars in the field today to ask further questions about indigenous literacies and cultural production in the nineteenth century, which will move nineteenth-century study and western literary studies forward in new and needed directions. Placing an emphasis on pedagogy and classroom strategies, this essay offers several approaches, texts, and authors that meld critical regionalism and a revitalized exploration of nineteenth-century American literature through the US-Mexican War.