Answer:
The U.S. Congress banned trade with South Africa
Step-by-step explanation:
With the end of the Apartheid Act of 1948, which was an extended part of racial discrimination that existed earlier, the foreign relations with U.S. had come to an end. The attempt to integrate South African supremacy over Southern Africa has failed in the year 1970, which put an end to the foreign intervention in Angola and Namibia.
As a result of Sharpeville Massacre, South Africa was abandoned from UN for their apartheid policies. US congress forced in maintaining distance between the two countries in almost every aspect as well as trade.