This story traces the complex and fascinating drama of the anti-apartheid movement in one of South Africa's most important allies, the United States. The US is a key battleground, with African-Americans at the center of the struggle. The campaigns take place in boardrooms, universities, embassies, and finally in the US Congress itself, where a stunning victory is won against the formidable opposition of President Ronald Reagan. African-Americans, for the first time in history, have turned the tide and altered the direction of US foreign policy. The US, once the backbone of support for the apartheid regime as her ally in the Cold War, finally imposes sanctions on Pretoria. This is part 4 of a 6 part series on the global anti-apartheid movements, stretching from 1946-1990.