Floriano Peixoto was a Brazilian military officer and politician of the XIX° century (1839-1895). He was the first vice-president and second president of the Republic of Brazil following the abolition of the monarchy in 1889. He governed from 23 November 1891 to 15 November 1894 : the telegram we deal with is dated 3 September 1894, so towards the end of his term of office. The sender is Hercílio Luz, governor of the Brazilian state of Santa Catarina from 1894 to 1898. Nothing is known about their correspondence, and to the best of our knowledge, this telegram is the first subjected to cryptanalysis. Many factors made this a complicated period for Brazil. The content of the message deals with the articulations of an election that took place in 1894. It is something revealing in terms of the political history of Brazil, as it reveals that the then president of the republic intensely articulated the election of deputies outside the Rio de Janeiro/Sao Paulo axis (the most important cities in the country at the time) and that is something new. The main difficulty for decryption lies in the fact that no historical cryptography study has focused on the encryption methods used in South America by local people.