Nelson Mandela was released from prison because of internal and external political pressures that encouraged the South African government to end apartheid. In an effort to gain international favor and appease opposing forces within the country, President F.W. de Klerk released all prisoners of the African National Congress, including Mandela.
In the decades leading up to Mandela's release, global public opinion began to turn against segregationist tendencies and toward racial equality. Religious leaders and leading diplomats from the major nations of the world began to pressure South Africa to repeal its apartheid policies. Banks and investment firms withdrew from the country. In the face of this pressure, de Klerk realized that apartheid was unsustainable. According to the Nelson Mandela Foundation, he ultimately released Mandela on Feb. 11, 1990.