This chapter analyzes the works of brother and sister Lucio Victorio Mansilla and Eduarda Mansilla, two fundamental figures in the cultural life of nineteenth-century Argentina, whose personal trajectories took them to Europe and the United States. Journalist, military man, and politician Lucio penned what can be considered the first ethnographic record of the Indigenous peoples of the Pampas; Eduardo was an accomplished novelist, travel writer, journalist, and musician who published in both Spanish and French. In this chapter the work of both siblings is read together. It takes into account the centrality of Lucio in the field of Argentinean literature and proposes that Eduarda illuminates different areas of the cultural intellectual life of nineteenth-century Argentina. Focus is on Una excursión a los indios ranqueles (1870) by Lucio V. Mansilla and two novels by Eduarda Mansilla – El médico de San Luis (1860) and Pablo ou la vie dans les pampas, published in French in 1869 and translated by Lucio – to reflect on the relationship between narration and the state, practices of everyday life, sociability, and family stories, as well as their circulation and consecration mechanisms.