Final answer:
The two nationalist parties formed in response to Ian Smith's declaration of independence for Rhodesia were the Zimbabwe African People's Union (ZAPU) and the Zimbabwe African National Union (ZANU).
Step-by-step explanation:
Following Ian Smith's declaration of independence for Rhodesia in 1965, there were two prominent black nationalist parties formed by the black working and middle class. These were the Zimbabwe African People's Union (ZAPU) led by Joshua Nkomo, and the Zimbabwe African National Union (ZANU) led by Robert Mugabe. The civil war that erupted as a result of this declaration was a significant event in the fight against racial control and oppression. ZAPU was supported by the Soviet Union, while ZANU received support from China. Eventually, all parties reached an agreement that led to the recognition of Zimbabwe's independence by the United Kingdom in 1980 and Robert Mugabe becoming the prime minister.