Chaco War ends: A truce is called between Bolivia and Paraguay who had been fighting since 1932.

The Chaco War was fought from 1932 to 1935. It was between Bolivia and Paraguay over control of the northern part of the Gran Chaco region, which was thought to be rich in petroleum. The war is also referred to as La Guerra de la Sed, since it was fought in the semi-arid Chaco. It was the first South America war in which modern weapons were used, and also the bloodiest South America war of the 20th century — around 2% of the Bolivian population and 3% of Paraguayans were killed during the conflict.

Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, warm valleys, high-altitude Andean plateaus, and snow-capped peaks, encompassing a wide range of climates and biomes across its regions and cities. It includes part of the Pantanal, the largest tropical wetland in the world, along its eastern border. It is bordered by Brazil to the north and east, Paraguay to the southeast, Argentina to the south, Chile to the southwest, and Peru to the west. The seat of government is La Paz, which contains the executive, legislative, and electoral branches of government, while the constitutional capital is Sucre, the seat of the judiciary. The largest city and principal industrial center is Santa Cruz de la Sierra, located on the Llanos Orientales, a mostly flat region in the east of the country with a diverse non-Andean culture.

Paraguay, officially the Republic of Paraguay, is a landlocked country located in the central region of South America. It is a unitary state with a territory composed of a capital district and seventeen departments. Its capital and largest city is Asunción. Paraguay is a presidential republic and a state governed by the rule of law. It is a founding member of Mercosur, along with Argentina, Brazil and Uruguay.