In parallel, growing prosperity encouraged a rapid rise of a new working class of Southern and Eastern European immigrants who contributed to the growth of trade unionism, anarchism, and socialism in Brazil.

According to historian Benjamin Keen, the task of transforming society "fell to the rapidly growing urban bourgeois groups, and especially to the middle class, which began to voice even more strongly its discontent with the rule of the corrupt rural oligarchies".

[4] In contrast, despite a wave of general strikes in the post-war years, the labour movement remained small and weak,[5] lacking ties to the peasantry, who constituted the overwhelming majority of the Brazilian population.

What became known as the tenentist movement came to public notice on 5 July 1922 when a group of young army officers began a rebellion against the First Brazilian Republic at Fort Copacabana in Rio de Janeiro.

Sparked initially by the punishment and brief imprisonment of marshal Hermes da Fonseca by president Epitácio Pessoa, the tenentes attempted to prevent Artur Bernardes, winner of the 1922 presidential election, from taking office.

Commanded by retired General Isidoro Dias Lopes, with the participation of several lieutenants, the main objective of the uprising was to depose President Artur Bernardes (considered to be an enemy of the military since the crisis of the fake letters).

The loyalist Army (loyal to President Artur Bernardes) used the so-called "terrifying bombardment", reaching various parts of the city, especially working-class neighborhoods such as Mooca and Brás, and the middle class, such as Perdizes.

Without equivalent military equipment (artillery or aircraft) to confront government troops, the rebels retired to Bauru in the early hours of July 28, where Isidoro Dias Lopes heard news that the legalist army was concentrated in the city of Três Lagoas, Mato Grosso do Sul.

[10] The formal leader was retired General Isidoro Dias Lopes, with others including Eduardo Gomes, Newton Estillac Leal, João Cabanas and Miguel Costa.

[10][11] The rebels in the city were put under siege by government forces, and prevented from linking up with other uprisings which were breaking out in places such as Bela Vista, Mato Grosso, Aracaju, Sergipe and Manaus.

They became known as the Prestes Column, and covered some 25,000 kilometres from October 1924 to February 1927 as they roamed through the interior of the country seeking unsuccessfully to promote mass rebellion or at any rate to act as a moral gadfly to the nation's conscience.

[14] After losing significant numbers to desertion and sickness, escaping encirclement at Palmeira, Rio Grande do Sul, in January 1925, making a successful stand at the Iguazu Falls in February[15] and after some initial disagreements about strategy, the rebels adopted one that amounted less to a war of movement than a moving "armed protest demonstration" that would serve as a constant call to action against the hated president Bernardes.

The farmers sympathised with us for the simple reason that we were against the oppressors, they admired our heroism and devotion, but had no intention (with rare exceptions of some young people) of committing themselves to a struggle in whose success they could not believe".