Standing trial for sabotage and attempting to overthrow the South African government in April 1964, Nelson Mandela could have pleaded for his life or he could have spoken out for what he believed in.
Mandela — who fought an official South African policy of racial discrimination for decades — chose his cause.
"I have cherished the ideal of a democratic and free society in which all persons will live together in harmony and with equal opportunities," Mandela told his judges in a Pretoria, South Africa, courtroom. "It is an ideal for which I am prepared to die."
The judges sentenced Mandela to life, and he remained imprisoned until 1990.
Recovering Mandela's Voice
Now, the British Library's National Archives is releasing a newly restored recording of his three-hour 1964 speech. It was originally made by a court stenographer on a dictabelt, a plastic recording never meant to preserve history.
However, after the recording was discovered by the South African Broadcasting Corp., experts at the British Museum were able to draw out Mandela's voice once again.
"What we had to do was very gently heat them so that we could actually get rid of the crease so that we could actually put this back into the machine and you'd get a continuous loop of sound," said Greg Hayman of the British Museum.
The recordings are being released in CD form in Britain this week.
"What amazed us, given the age and fragility of these dictabelts, is just how good the sound quality is," said Rob Perks, the British Library's oral history curator.
Mandela was born in South Africa's Transkei region in 1918, the son of the region's most powerful chief. He studied law in Johannesburg and helped found the African National Congress Youth league in 1944.
Discrimination against the majority black South African population was written into law after the 1948 election victory by the National Party, whose membership was dominated by the white settlers of Dutch descent, known as the Afrikaners.
'Freedom for All'
In 1962, Mandela was sentenced to five years in jail after being found guilty of sabotage and attempting to overthrow the government.
In 1964, Mandela and 15 other leaders of the African National Congress were charged with plotting to overthrow the state. Escaping the death penalty, the group was sentenced to life imprisonment.
On the recording, Mandela explained why he continued to fight on.
"The whites enjoy what may well be the highest standard of living in the world, while Africans live in poverty and misery," he said. "The lack of human dignity experienced by Africans is the direct result of the policy of white supremacy.
"When anything has to be carried out, or cleaned, the white man will look around for an African to do it for him, whether the African is employed by him or not," he added. "Because of this sort of attitude, whites tend to regard Africans as a separate breed."
"I know this sounds revolutionary to the whites in this country, because the majority of voters will be Africans. This makes the white man fear democracy," he said. "But this fear cannot be allowed to stand in the way of the only solution which will guarantee racial harmony and freedom for all."
Mandela spent many years on the notorious Robben Island off Cape Town, carrying out hard labor in a lime quarry.
After 27 years of jail, Mandela was released in 1990 and a year later, named president of the ANC.
In 1994 Mandela made history when he became South Africa's first elected black president, putting an end to the apartheid regime.
ABCNEWS' Jennifer Sterling and Sheila MacVicar, both in London, contributed to this report.