Which South American capital is the southernmost national capital in the Americas? Montevideo, Uruguay.
Montevideo occupies the northern shore of the Río de la Plata in Uruguay’s Southern Cone. Its position farther south than Buenos Aires and every other capital of an independent American nation gives it the distinction of being the Americas’ southernmost national capital.
The city was established by the Spanish in the 1720s as a strategic military settlement during the rivalry between Spain and Portugal. Its deep natural harbor helped it grow into Uruguay’s principal port, commercial center, and largest city. Montevideo later became the capital of independent Uruguay, whose constitution was adopted in 1830.
The wording matters: Montevideo is not the southernmost capital of any kind in the world. Wellington and Canberra lie farther south globally. Nor is it the southernmost city in the Americas; places such as Ushuaia and Puerto Williams are much farther south, but they are not national capitals.