Argentine authorities worried the strong connections araucanized tribes had with Chile that allegedly gave Chile certain influence over thepampas. Argentine authorities feared an eventual war with Chile over Patagonia where the natives would side with the Chileans and that it would therefore be fought in the vicinities of Buenos Aires.
The decision of planning and executing the Conquest of the Desert was probably triggered by the 1872 attack of Cufulcur� and his 6,000 followers on the cities of General Alvear, Veinticinco de Mayo and Nueve de Julio[ where 300 criollos were killed, and 200,000 heads of cattle taken.
In the 1870s the Conquest of the Desert was a controversial campaign by the Argentine government, executed mainly by General Julio Argentino Roca, to subdue or, some claim, to exterminate the native peoples of the South.
In 1885 a mining expeditionary party under the Romanian adventurer Julius Popper landed in southern Patagonia in search of gold, which they found after travelling southwards towards the lands of Tierra del Fuego. This further opened up some of the area to prospectors. European missionaries and settlers arrived through the 19th and 20th centuries, notably the Welsh settlement of the Chubut Valley.
During the first years of the 20th century, the border between the two nations in Patagonia was established by the mediation of the British crown. But it has undergone a lot of modifications since then, and there is still one place (50 km long) where there is no border established (Southern Patagonia Icefield).
Until 1902, a large proportion of Patagonia's population were natives of Chilo� Archipelago (Chilotes) who worked as peons in large livestock farming estancias. As manual labour they had status below the gauchos and the Argentine, Chilean and European landowners and administrators.
