The Social Democratic Federation (SDF), founded in Cape Town in 1904 and open to socialists of all persuasions, had an active anarchist wing. A notable revolutionary syndicalist formation was the International Socialist League (ISL). Founded in Johannesburg in September 1915, the ISL established branches across much of South Africa (excluding the western Cape) and organised the first black African trade union in the country, the Industrial Workers of Africa (IWA) – influenced by the Industrial Workers of the World (IWW) – in September 1917. In 1918, the anarchists and syndicalists in Cape Town left the SDF to form the revolutionary syndicalist Industrial Socialist League, which supported the IWA in the western Cape and also formed its own syndicalist union in food processing factories. The ISL and Industrial Socialist League, which developed an alliance, also formed a number of other unions among people of colour. While their founders were mainly drawn from the radical wing of the white working class, the movement would develop a substantial black African, Coloured and Indian membership.