Acquired from Bolivia under the Petrópolis Treaty, signed in 1903, Acre was the last area to be integrated into Brazilian territory. At the time, this merger served the interests of sectors involved in the exploitation of rubber.
Until the 19th century, Acre belonged to Bolivia and was inhabited exclusively by indigenous groups. From 1877 onwards, migrants from the Northeast, fleeing the drought and recruited to work in the extraction of rubber latex and rubber production, began to arrive, an item that was highly valued at the time. Thousands of Brazilians reached this area, following the valleys of the Acre, Purus and Juruá rivers.
Concerned about the Brazilian presence, the Bolivians founded the city of Puerto Alonso to be the administrative headquarters that would take care of the collection of taxes on rubber. There were armed conflicts and the Brazilians occupied the city, changing its name to Porto Acre.
Determined to recover positions, in 1901 the government of Bolivia handed over Acre to the care of an American group, The Bolivian Syndicate, which would take charge of the economic exploitation of the territory. The measure provoked reactions not only from the rubber tappers, but also from the Brazilian government, which protested the foreign presence in the region.
In 1902 there was a new onslaught by the rubber tappers, led by the gaucho José Plácido de Castro, who occupied Puerto Alonso and declared the independence of Acre. In this phase of great tension, Brazilian diplomacy mobilized and compensated the Americans for £ 110,000 for breaking the exploration contract in the region. At the same time, it negotiated the purchase of Acre with the government of Bolivia.
Signed in November 1903, the Petrópolis Treaty provided for the payment of two million pounds sterling to Bolivia and the construction of the Madeira-Mamoré railway in exchange for the Acre lands. The railway was intended to facilitate the flow of products from Bolivia, which has no outlet to the sea, to the Amazon basin and from there to the Atlantic.
The Madeira-Mamoré railway
Built between 1907 and 1912, its purpose was to connect with the latex producing areas, close to the Madeira, Mamoré, Guaporé and Beni rivers, located in Bolivia. The work was seen as extremely bold for the time, due to the difficulty of building a railway of that size in the middle of the forest. In practice, the construction proved to be even more arduous than expected, due to the isolation of the area and the difficulty of equipment arrival.
It is estimated that 30,000 people worked on the project, of which 6,000 would have died as a result of occupational accidents or tropical diseases, such as malaria. Ironically, the advance of the so-called “Ferrovia da Morte” rails coincided with the decline of national rubber production. Due to the difficulties faced in its construction, Madeira-Mamoré was never completed, but it worked until 1972, when it was deactivated.