OLASCOAGA (Manuel J.). The Conquest of the Pampas. Collection of documents relating to the Rio Negro campaign. Buenos Aires, Printed by the "Courrier de la Plata", 1881. Small in-4, aubergine half-basin (period binding). "An accurate account of the campaign that brought the military frontier to the Rio Negro, established civilisation in the southern lands of the Republic and destroyed Indian domination forever. The work includes a large folded map in colour (reinforced folds).