In May 1910 the Union of South Africa came into being as unitary state comprising the former colonies of Cape of Good Hope, Natal, Orange River Colony, and the Transvaal. The colonists in this new Union were of British and Dutch extraction and much effort was expended bringing these two cultures together. As a result the African population of the country became marginalised and even repressed by the new white hegemony.
Following the foundation of the Union, many African intellectuals felt that there was a need for a new national movement to represent the native peoples. Not least among these was the lawyer, Pixley ka Isaka Seme, who advised that representatives of all the ethnic groups should meet to discuss their common welfare. Consequently, on 8th January 1912, delegates from all four provinces as well as from Botswana met in Bloemfontein under the banner of unity.
The delegates included tribal chiefs, intellectuals, religious leaders and other representatives of the various ethnic groups. During the keynote address Semi declared,
Chiefs of royal blood and gentlemen of our race, we have gathered here to consider and discuss a theme which my colleagues and I have decided to place before you. We have discovered that in the land of their birth, Africans are treated as hewers of wood and drawers of water. The white people of this country have formed what is known as the Union of South Africa – a union in which we have no voice in the making of the laws and no part in their administration. We have called you therefore to this Conference so that we can together devise ways and means of forming our national union for the purpose of creating national unity and defending our rights and privileges.
The ANC website includes a number of documents about the history of the organisation.