Nelson Mandela was the prominent anti-apartheid activist in South Africa known for his lengthy prison sentence. His resistance against the oppressive apartheid regime, which enforced racial segregation and discrimination, led to his arrest in 1962 and subsequent imprisonment for 27 years. Mandela emerged as a symbol of the struggle for justice and equality, capturing international attention as various campaigns highlighted his imprisonment. Upon his release in 1990, he played a crucial role in negotiating the end of apartheid and fostering reconciliation in South Africa, later becoming the country's first black president in 1994.