Anarchism was an influential contributor to the social politics of the First Brazilian Republic. During the epoch of mass migrations of European labourers at the end of the nineteenth and the beginning of the twentieth century, anarchist ideas started to spread, particularly amongst the country’s labour movement. Along with the labour migrants, many Italian, Spanish, Portuguese and German political exiles arrived, many holding anarchist or anarcho-syndicalist ideas. Some did not come as exiles but rather as a type of political entrepreneur, including Giovanni Rossi's anarchist commune, the Cecília Colony, which lasted few years but at one point consisted of 200 individuals.

The Sortition Law, officially Law No. 1,860 of 4 January 1908, introduced compulsory military service for the Brazilian Armed Forces. It was approved in 1906 but only de facto implemented in 1916, replacing forced recruitment - the antiquated "blood tribute" - and allowing the formation of a reserve. Sortition or draft lottery was the mechanism used for recruiting soldiers from 1916 to 1945, when it was replaced by general class call, which is the mandatory military service system in 21st century-Brazil. An earlier law of 1874 had already introduced the lottery, but it was not applied due to popular resistance. Also controversial, the 1908 law was one of the major military reforms of the First Brazilian Republic and had lasting effects on the Brazilian Army's relationship with the country's politics and society. The arguments advanced by lottery advocates in 1908–1916 remain the official justifications for conscription a century later.