Battle of Río Grande
1879 CE.
Shown on the map at -22.804°, -68.199°.
The Battle of Río Grande was a minor military engagement that took place on 10 September 1879, during the War of the Pacific. A picket of Chilean soldiers and a Bolivian montonera clashed in Rio Grande, around San Pedro de Atacama. The Bolivians are defeated, which eliminates local resistance to Chilean occupation in the Litoral Department.
Text from the Wikipedia article Battle of Río Grande, licensed CC BY-SA 4.0.