Flags at the White House are flying at half-staff to honor Nelson Mandela's legacy. Throughout his life, Mandela earned the respect of countless leaders including U.S. presidents past and present.

Harvard Law Professor Charles Ogletree knew Nelson Mandela and spoke to Anderson about his legacy. Ogletree says he expected Mandela to live forever "even when he was sick and it was clear he was going to die."

Nelson Mandela helped Richard Branson start a humanitarian group. Branson talks to Anderson about how Mandela's ability to forgive helped heal the wounds of apartheid, avoid a civil war and make South Africa one of the great nations.