The IWW (SA) established a stronghold in Johannesburg in June 1910 with a Scottish immigrant, Andrew Dunbar, as its first general secretary. Dunbar had immigrated to South Africa in 1906 and worked on railways in Natal as a blacksmith, but had been blacklisted as a result of leading a mass strike in 1909. After finding work on the Johannesburg tramways, Dunbar immediately went about organizing the predominantly white workers there. A major strike was waged in 1911 and won despite intense police repression. Despite this success, Dunbar, an anarchist, was ousted from his position under accusations of "intolerance, unpredictable behavior and intemperate attacks on comrades" in February 1912. Some accounts characterize this as a purge perpetrated by a faction led by Archie Crawford, the editor of Johannesburg's left-wing Voice of Labour newspaper. Crawford, a parliamentary socialist, was convinced that the IWW should affiliate itself with United Socialist Party in contradiction with the union's principles and Dunbar, in opposition to this idea, fell victim to Crawford's growing influence. Crawford would eventually abandon the idea of formal USP affiliation but became a leading figure in the union, going on a world tour speaking on behalf of the IWW (SA) and establishing closer contact to IWW sections in Australia and the United States.
