Reasons for Nelson Mandela's Imprisonment:

Rivonia Trial:
- Nelson Mandela was imprisoned primarily due to his involvement in the Rivonia Trial in 1964.
- Mandela and several other anti-apartheid activists were charged with sabotage and conspiracy to overthrow the government.

Anti-Apartheid Activities:
- Mandela was a key figure in the anti-apartheid movement in South Africa, fighting against the racist policies of the apartheid government.
- His involvement in protests, strikes, and other activities aimed at ending apartheid led to his arrest and imprisonment.

ANC Leadership:
- Mandela was a prominent leader of the African National Congress (ANC), an organization that opposed apartheid and fought for the rights of black South Africans.
- His leadership role in the ANC made him a target for the apartheid government, which sought to suppress opposition to its policies.

27 Years in Prison:
- Mandela was sentenced to life in prison as a result of the Rivonia Trial, and he spent 27 years behind bars.
- During his time in prison, Mandela became a symbol of the anti-apartheid movement, inspiring people around the world with his resilience and commitment to justice.

Release and Presidency:
- Mandela was finally released from prison in 1990, after years of international pressure and internal resistance to apartheid.
- He went on to become the first black president of South Africa in 1994, leading the country through a peaceful transition to democracy and reconciliation.