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(CNN) - When former President Jimmy Carter met Nelson Mandela, the first thing the South African leader did was congratulate Carter on his daughter Amy.
"(Amy) had been arrested three times in college for demonstrating against apartheid in South Africa," Carter said in a phone interview with CNN's "The Lead with Jake Tapper."
"We got off to a good start, and we maintained our friendship right up until the end of his life," said Carter.
Read: Nelson Mandela, anti-apartheid icon and father of modern South Africa, dies
When Mandela was elected leader of South Africa, his jailers sat in the front row at his inauguration. He insisted that official staff remain at the capital, even though many of them had been part of an apartheid, oppressive, racist system.
"He's been almost absolutely undeviating in his ability to forgive people who hurt him personally, and hurt the people that he loved. And that was the Nelson Mandela I knew," said Carter.
Mandela was also a controversial figure. He praised figures many would argue do not deserve high regard, such as Cuban leader Fidel Castro, and longtime Libyan dictator Moammar Gadhafi.
Until recently, Mandela was considered a terrorist by the U.S. government for waging battle against the apartheid government of South Africa.
"They only removed him two Junes ago. That doesn't prove that there's anything wrong with him, it's just a matter of the United States making a mistake in declaring him and all the members of the African National Congress as terrorists," said Carter.
When Carter was president, he "tried every way I could" to end apartheid in South Africa.
"But then when President Reagan came into office, he really undid the things that we did and tried to preserve the apartheid government," said Carter. "So the United States government's policies have changed back and forth, and other nations have looked upon Nelson Mandela and his organization in different capacities."
"But what (Nelson Mandela) has done has been right," said Carter. "After he was finally released from 27 years of imprisonment, his attitude was one of forgiveness and reconciliation, and building a better nation for his people."
Carter first met Mandela and his wife Winnie in Addis Ababa, Ethiopia, in 1990, during a meeting of the Organization of African Unity.
Since then, Mandela has helped with several projects spearheaded by The Carter Center. In recent years, Carter worked with Mandela through The Elders, a group of former world leaders co-founded by Mandela that works to encourage the resolution of conflicts, and advance social justice and human rights around the world.
But Carter said even before he met the iconic leader, he was inspired by him.
"Nelson has meant a lot to me, obviously when he was still in prison, as an inspiration of a courageous, and embattled, and abused person who didn't want to fight back and continue with violence," said Carter.
Carter even visited Mandela in his home. Carter's grandson Jason had served in the Peace Corps in South Africa and spoke Zulu. He pleaded with the former president to take him along because, as Jason told his grandfather, "I always wanted to meet someone who went to prison before they were in public office."
So Carter brought Jason to Mandela's home, and found himself sidelined at the visit.
"They spent that whole half an hour talking to each other in Zulu, and pretty well ignored me, the former president of the United States," said Carter, with a laugh.