The War of the Pacific was a war between Peru, Bolivia and Chile (the first two allied) in which Chile won. Chile gained the provinces of Tarapacá, Antofagasta, Arica and Tacna (this last one was given back to Peru in 1929) in where Chile obtained numerous reserves of Saltpeter, Copper and Lithium that sustain the Chilean Economy.
Bolivia lost all of its coastal territory but maintains sea access via Chilean and Peruvian ports in the Pacific as well as Uruguayan in the Atlantic with economic royalties.