East Patagonia, Tierra del Fuego and Strait of Magellan dispute

The East Patagonia, Tierra del Fuego and Strait of Magellan Dispute or the Patagonia Question was the boundary dispute between Argentina and Chile during the 19th century for the possession of the southernmost territories of South America on the basis of disagreements over the boundaries corresponding to the uti possidetis juris inherited from the Spanish Empire, which were partly due to contradictory background information. The extensive territory corresponds to approximately one million square kilometres, which represents 45% of the current surface of Argentina, all of the center and south of that country, and which, according to Chilean historiography, would have implied a loss for Chile of two-thirds of its nominal territory de jure.

Source: Wikipedia — East Patagonia, Tierra del Fuego and Strait of Magellan dispute (CC BY-SA 4.0)