Historedia
AmericasEvent

The Boundary Treaty of 1881 between Chile and Argentina is signed in Buenos Aires

When
1881
Where
Buenos Aires
Episodes
1

The Boundary Treaty of 1881, signed in Buenos Aires on 23 July 1881, established a precise border between Chile and Argentina based on the uti possidetis juris principle. Signatories included Bernardo de Irigoyen for Argentina and Francisco de Borja Echeverría for Chile. The treaty laid the groundwork for nearly all of the current 5600 km border, dividing largely unexplored lands.

Episodes

  1. 23 July 1881 · Buenos AiresSigning of the Boundary Treaty

    Bernardo de Irigoyen and Francisco de Borja Echeverría signed the treaty in Buenos Aires on 23 July 1881 to establish a precise border.

Background and detail

Negotiation. Chile was engaged in the War of the Pacific against Bolivia and Peru. Argentina had taken advantage of Chile's conflict to push for a favorable boundary in Patagonia. However, Chilean diplomacy only agreed to sign the treaty after the triumph at Lima demonstrated Chile's position of power. The treaty aimed to establish a precise border based on the uti possidetis juris principle.

Terms. The treaty defined the boundary from north to south as far as the 52nd parallel of latitude, following the Cordillera de los Andes. It allocated islands, assigning Staten Island and Atlantic islands to Argentina, and islands south of the Beagle Channel and west of Tierra del Fuego to Chile. The agreement adhered to the three-nautical-mile territorial sea practice of the time.

Sources

  1. Boundary Treaty of 1881 between Chile and Argentina Wikipedia, revision of 2026-08-18

Machine-drafted from the cited Wikipedia passages and checked by a reviewing model, not by a human editor. Every passage cites the revision it was written from; dates and places follow those passages.