The treated of Petrópolis was signed between the Bolivia and the Brésil in 1903 in the town of Petrópolis.

By this treaty, the Brésil buys with the Bolivia the territory of the State of the Acre in exchange of 2 million pounds sterling, of grounds of the Mato Grosso and the construction of a way of railroad making it possible to run out the Bolivian production towards the the Amazon.

At the beginning of the 20th century, this territory, pertaining to Bolivia was already occupied by Brazilian Seringueiro S in full boom of the rubber. To solve the tensions which resulted from this occupation, the baron de Rio Branco started negotiations which led to the treaty of Petrópolis. ----