Dec. 5, 2013 -- In the 27 years that Nelson Mandela spent imprisoned in South Africa, he wrote letters to his loved ones.
Razia Saleh of the Nelson Mandela Foundation is part of a team that has spent considerable time cataloging these historical snapshots from Mandela's life before he became the first president of South Africa to be chosen in a fully representative democratic election.
In the early years, Mandela -- sentenced in 1964 to life imprisonment -- was only allowed to write one letter every six months. He was forced to choose his words carefully so they could get past his jailers and be read by those he longed to speak with.
He repeatedly asked for permission to write more letters than he was allowed. After learning that his wife Winnie was having heart trouble, he asked the guards in their Afrikaans language, hoping it would persuade them to change their minds.
In his notebooks, he would write a first draft of every letter, cataloging his thoughts from his days imprisoned on Robben Island and later in Pollsmoor Prison.
When he was released on Feb. 11, 1990, he carried with him his treasured correspondence.
"He walked out with it when he left prison, so he took it with him," Saleh told ABC News' David Muir.
The handwritten letters in his notebook to his children were reassuring.
"I do not know, my darlings, when I will return," Mandela wrote. "I told you that the white judge had said I should stay in jail for the rest of my life. It may be long before I come back. It may be soon. Nobody knows when it will be, not even the judge who said I should be kept here."
Mandela also wrote to a cherished friend he had not heard from in some time.
"Do you forget your friend so easily? Why are you not writing?" he asked. "Why have you not written?"
On his 71st birthday, a note documented a visit from Winnie, his children and grandchildren. The real gift to the future president would come a year later, when he was released from prison as the whole world watched.
Mandela never seemed to waver in his optimism for the future, recalled in a promise he made to his children two decades before he was freed.
"I am certain that one day I will look back," he wrote. "I will be back at home to live in happiness until the end of my days."