After the Pulacayo silver mine was rediscovered in 1833, Aniceto Arce acquired it in 1856, and it became the foremost holding of his Huanchaca Company. While serving as Bolivian president (1888–92), Arce established railroad connections between Pulacayo and Antofagasta on the Chilean coast in 1890 and with Oruro in 1892. After 1927, the tin magnate Mauricio Hochschild held possession of the valuable mine. Given the economic importance of Pulacayo, it is no coincidence that the site would become a leading center for the organization of mineworkers. The Trade Union Federation of Bolivian Mineworkers (fstmb) was founded in 1944, and in November 1946, conscious of the workers’ pivotal role in national production, it issued the radical document that became known as the Thesis of Pulacayo, which was delivered at the site during the union’s First Special Congress. Its demands transcended the typical concerns of trade-union struggle—salary and working conditions—to address national and international conditions and the strategy for a revolutionary seizure of power. It carried the Trotskyist stamp of the Revolutionary Workers Party (por) and followed the party doctrine of “permanent revolution.” The theory held that in an underdeveloped country like Bolivia, there was no bourgeoisie to carry out the initial transition from feudalism to capitalism, and therefore it was incumbent on the proletariat, joined by the peasantry, to seize power and introduce democracy, agrarian transformation, and freedom from imperialism while simultaneously ushering in socialism. The por—led by Guillermo Lora, the principal author of this “thesis,” and by the trade-union representative Juan Lechín—carried great weight within the fstmb, and the Pulacayo document functioned as the organization’s guiding light until the 1980s.