(1909), act that unified the British colonies of Cape Colony, Natal, Transvaal, and Orange River and thereby established the nation of South Africa. It was the work of white delegates to a national convention at Durban, Natal, in 1908, who represented white electorates, less than one-fifth of the population of South Africa.

The constitution agreed upon at Durban was largely the work of Jan Smuts (Smuts, Jan), colonial secretary of the Transvaal (and of his English secretary, R.H. Brand), and was modeled on the Australian constitution of 1900. Most power was to be concentrated in the all-white union Parliament, effectively disfranchising blacks (racism). Before the convention Smuts and John X. Merriman (Merriman, John X.), prime minister of the Cape Colony, had agreed that a “colour-blind” franchise (i.e., one not excluding nonwhites) should be confined to the Cape Province and, even there, should be subject to constitutional amendment. The amendment procedure—two-thirds majority of both houses sitting together—also applied to the clause guaranteeing equal status to whites of either English or Dutch descent. Cape African and Coloured (persons of mixed race) voters also lost their right (never exercised) of electing people of their own class to Parliament. The political colour bar was thus enshrined in the constitution. One of the political issues that most vexed the delegates was that of the capital of the new union; finally a compromise was reached, with Pretoria becoming the administrative, Cape Town the legislative, and Bloemfontein the judicial capital.

The draft constitution was passed as an act of the British Parliament in 1909, and the union was inaugurated on May 31, 1910, with Louis Botha as the first prime minister. Many British members of Parliament and some white South African politicians were aware of the discriminatory nature of the new act, but it was argued that the political and economic advantages of union would outweigh the disadvantages.