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

The Boundary Treaty of 1881 between Chile and Argentina, also known as the Treaty of 1881, was an agreement signed on July 23, 1881, aimed at resolving territorial disputes between the two countries in the Patagonia region.

Defining the Boundary: The treaty established the boundary between Chile and Argentina from the Andes Mountains to the southernmost tip of South America. It defined the border along the highest peaks of the Andes that divide the waters flowing to the Pacific and Atlantic Oceans.

Specific Regions:
Northern Section: The boundary was defined from the 23rd parallel south to the 26th parallel south along the Andes Mountains.
Central Section: The boundary followed the watershed line of the Andes from the 26th parallel south to the 52nd parallel south.
Southern Section: South of the 52nd parallel, the boundary followed a more detailed line through the southern islands and channels, including Tierra del Fuego, where the island was divided between the two countries.

Tierra del Fuego: The island of Tierra del Fuego was divided along a meridian, giving the eastern part to Argentina and the western part to Chile, including the Strait of Magellan, which remained under Chilean sovereignty.

Recognition of Sovereignty: The treaty recognized Chile’s sovereignty over the Pacific Ocean side and Argentina’s sovereignty over the Atlantic Ocean side.

Peaceful Resolution: The treaty was intended to peacefully resolve disputes and prevent conflicts between the two nations, fostering cooperation and good relations.