Step-by-step explanation:
The gains achieved by the White minority in the first four decades of the 20th century were, by the 1940s, increasingly under threat however, as African resistance to the racially based system rapidly escalated. This crisis was brought to a head by the continuing decline of the reserve economies. Full proletarianisation in South Africa, would threaten the migrant labour system upon which White profitability depended. This crisis coincided with rapid secondary industrialisation and a substantial growth of urban African populations, as well as growing trade union activity and rising African working class militancy. These developments were threatening not only the conditions for accumulation but White political hegemony itself.