The South Africa Act came into force on May 31, marking a significant administrative transformation in southern Africa. This act united the Cape Colony, Natal, Transvaal, and Orange Free State into a singular political entity— the Union of South Africa. Influenced by the desire for greater self-governance within the British Empire and the political dynamics following the Second Boer War, the act was intended to create a new, coherent government that would streamline administration and address the complexities of colonial governance. The Union was established as a dominion, which held legislative power under the British crown. The notion behind the Union was to consolidate the various political interests of the colonies into one parliamentary system, enabling unified responses to issues such as land ownership and citizenship. The first elections were subsequently held in September of the same year, signaling a foundational shift in political governance in the region.

The Union was a compromise between English and Afrikaans speakers, reflecting the social dynamics of the region after extensive conflict. The Act established a bicameral parliament, comprising a House of Assembly and a Senate, with provisions that prioritized white political power while systematically disenfranchising non-white populations. As a result, it became a framework for governance that subsequently institutionalized racial segregation and discrimination, which would culminate in the apartheid system decades later. Institutions and policies were created to maintain social order and control over the native population, inherently shaping the socio-political landscape of modern South Africa.

The establishment of the Union of South Africa represents not only an integration of smaller territories but also a significant milestone in colonial transformation. It set the stage for a complex interplay of racial, economic, and political factors that would have long-lasting repercussions for the country. The Union ostensibly aimed to balance various interests, yet it solidified a governmental structure that enshrined racial inequality. This act opened pathways for subsequent legislation that molded South Africa's future trajectory, underlining the powerful role of governance in shaping societal norms and relationships.