On November 15, 1889, Marshal Deodoro da Fonseca deposed Emperor Pedro II, declared Brazil a republic, and reorganized the government. According to the new republican Constitution enacted in 1891, the government was a constitutional democracy, but democracy was nominal. In reality, the elections were rigged, voters in rural areas were pressured or induced to vote for the chosen candidates of their bosses (see coronelismo) and, if all those methods did not work, the election results could still be changed by one sided decisions of Congress' verification of powers commission (election authorities in the República Velha were not independent from the executive and the Legislature, dominated by the ruling oligarchs). This system resulted in the presidency of Brazil alternating between the oligarchies of the dominant states of São Paulo and Minas Gerais, who governed the country through the Paulista Republican Party (PRP) and the Minas Republican Party (PRM). This regime is often referred to as "café com leite", 'coffee with milk', after the respective agricultural products of the two states.

The Brazilian republic was not an ideological offspring of the republics born of the French or American Revolutions, although the Brazilian regime would attempt to associate itself with both. The republic did not have enough popular support to risk open elections. It was a regime born of a coup d'état that maintained itself by force. The republicans made Deodoro president (1889–91) and, after a financial crisis, appointed Field Marshal Floriano Vieira Peixoto Minister of War to ensure the allegiance of the military.