Abstract: This dissertation is a literary and cultural history of the intertwining of Yiddish, Spanish and English in the twentieth-century Americas. I employ a hemispheric lens to argue that across the Americas, Jewish authors imagined national belonging through different engagements with language. The project follows the literary production of eastern European Jews in Buenos Aires and New York—two major urban immigration centers—arguing that linguistic strategies and language politics undergird the struggle to balance “Americanization” with Jewishness as well as a hemispheric future with a European past. I follow this process of adaptation through paired writers working across the waves of eastern European migration from the late-nineteenth to late-twentieth century. What emerges is a historical continuum from the standard-language racial romances of Anzia Yezierska (circa 1890-1970) in the US and Alberto Gerchunoff (circa 1883-1950) in Argentina, to the English-language modernist experimentation of Henry Roth (1906-1995) and Waldo Frank (1889-1967), to the communist Yiddish-language work of Argentinian, Mimi Pinzón (1910-1975). Each author navigates Jewish Americanness through a world view profoundly shaped by language of publication. The question, “How did (European) Jews make themselves American?” has received much scholarly attention. This project, anchored in the transnational turns of American literary and Jewish studies, makes the question new by reading Jewish Americanness across the Americas. I explore the encounter between European notions of Jewish-belonging / un-belonging and American peoples and languages in the twentieth century. Thinking through language and across the Americas helps revise traditional understandings of Jewish Americanness. However, I argue that because the Jewish Americas are transnational and translational par excellence, they also help us rethink American identity writ large. By challenging the myth of two Americas—separated by Spanish and English histories and languages— as well as the notion that citizens must choose between cultural particularity and national loyalty, the Jewish Americas produce and demand trans-American theorizing.