Anarchism in Uruguay held a major importance in the organization of the labor movement. The history of the libertarian movement in Uruguay was closely linked to issues circulating internationally: the immigration of Spanish and Italian workers in particular had a major influence in its development, but the relations between revolutionary movements across Latin America, and in particular with Argentina and Brazil were equally significant.
In 1875, the "Regional Federation of the Eastern Republic of Uruguay" was founded in Montevideo on the initiative of French and Spanish revolutionaries, exiled following the destruction of the Paris Commune and the Cantonal Revolution respectively. Influenced by Mikhail Bakunin, the Federation of Montevideo officially joined the Anti-authoritarian International at the first session of the Congress of Verviers, on 6 September 1877, although it had already participated in a correspondence with the International for more than a year. The Anti-authoritarian International was then in decline, but the Federation of Montevideo managed to locally organize several hundred workers by creating associations by profession.
From the 1880s to the first years of the 20th century, the Uruguayan anarchist movement developed thanks to a multitude of affinity groups and ephemeral newspapers. Though the absence of a large organization did not make it possible to federate the libertarian movement, the amount of propagandist, educational, cultural and political initiatives allowed these ideas to spread within Uruguayan society, particularly in working-class districts.
In the first years of the 20th century, the Uruguayan proletariat strengthened its organization by founding the country's first trade unions. This movement led, in 1905, to the founding of the Uruguayan Regional Workers' Federation (Spanish: Federación Obrera Regional Uruguaya, FORU), based on the anarcho-syndicalist model of the FORA. This method of organization then dominated the Uruguayan workers' movement until the 1920s. The initiative for its foundation came from the Federation of Workers of the Port of Montevideo, which then brought together unions and resistance societies from many trades linked to port activity, as well as other centers of workers' and revolutionary organizations.
From 1905 to 1923, the FORU was the sole labor union in Uruguay. In 1922, FORU joined the International Workers' Association, but the consequences of the Russian Revolution led to a split in 1923, which put an end to twenty years of organizational unity among workers. In 1923, the Uruguayan Syndicalist Union (USU) was founded along anarcho-syndicalist lines, on the initiative of the Maritime Workers' Federation. The USU was opposed to the FORU on the question of its support for the Russian Revolution after the Bolshevik seizure of power. Meanwhile, the central brought together anarchists but also activists of the recently created Communist Party of Uruguay (however, they broke off in 1927 to found the Workers' Unity Bloc, which later became the General Confederation of Labor in 1929). State repression and competition from other socialist organizations gradually caused anarcho-syndicalism to lose its influence.