Bolivia's defeat by Paraguay in the Chaco War of 1932–1936 marked a turning point in the modern history of Bolivia. Great loss of life and territory discredited the traditional ruling classes, while service in the army produced stirrings of political awareness among the indigenous people. A large portion of the contested Gran Chaco region was surrendered to Paraguay. In return Bolivia was given access to the Paraguay River where Puerto Busch was founded and, with this, free access to the Atlantic Ocean through international waters was possible. In 1936 Standard Oil's Bolivian operations were nationalized and the state-owned firm Yacimientos Petroliferos Fiscales Bolivianos (YPFB) was created. From the end of the Chaco War until the 1952 Bolivian National Revolution, the emergence of conten