The Atacama border dispute began in the 1800s over the Atacama Desert, a section of northern Chile. The Atacama Desert is bordered by the Coast Range on the west and the Andes on the east. The geography of the area was a very large factor in determining how the border dispute began. Because of the mountains, the area has rains only 2 to 4 times a century, making it one of the driest places on Earth.

Boundaries in the Atacama region were never really determined. The Andes led to it being controlled by Chile, but when nitrates and copper were discovered there, it was also claimed by Bolivia. Nitrates are used in fertilizer, and copper could be mined, so both countries wanted the area.

A treaty was made in 1874 that allowed each country to mine part of it, and Bolivia wouldn’t raise taxes on Chilean products for 25 years. Four years later, Bolivia attempted to raise taxes on a Chilean nitrate company, so the Chilean army occupied Antofagasta, a Bolivian city. Chile declared war on Bolivia in March 1879, and on Peru in May 1879, therefore starting the War of the Pacific.

By the end of the war, Chile had captured the Atacama region as well as the province of Antofagasta, turning Bolivia into a landlocked state.

A treaty in the early 1900s officially recognized Chile as the owner of the Atacama, but allowed Bolivia free access to the sea, and has stayed that way. There hasn’t been very much dispute over the borders, except for the Chaco War, when Bolivia attempted to gain land from Paraguay that would connect them to the Atlantic Ocean.