Nelson Mandela was born in South Africa in 1918 and joined the African National Congress Youth League in 1942 to direct peaceful, nonviolent acts of defiance against South Africa's racist policies for 20 years. He was incarcerated on Robben Island for 18 of his 27 years in prison, where he contracted tuberculosis and received poor treatment. While imprisoned, he earned a law degree through correspondence. In 1990, President de Klerk announced Mandela's release and in 1993 they were jointly awarded the Nobel Peace Prize. Mandela then became South Africa's first democratically elected president in 1994.