Charleston Mayor Joe Riley recalls how impressed he was when he met Nelson Mandela about 20 years ago.

“What struck me first of all was his grace,” Riley said. “He put us at ease. He was warm and kind. He talked about how important the civil-rights movement in the United States was to him, while he was in jail persevering, to know the progress through courageous actions that was being made in the United States.”

Riley spent some time with Mandela in 1992 at a reception for mayors at the Democratic Convention in New York City. Mandela’s health declined in recent years, but 20 years ago, he was an energetic and impressive figure.

“He was taller than I had imagined,” Riley recalled, “fit and strong appearing. But he exuded humility. There was no sense of any self-importance. He was humble and gracious.”

Mandela, South Africa’s first black president, died Thursday at age 95. He spent a third of his life in jail because of his fight against the white racist system that kept blacks in his country as second-class citizens.

“He was one of the great heroes of our time and one of the great people in history,” Riley said. “His extraordinary courage and determination, withstanding the 28 years in jail, and the grace that he exhibited throughout that — and then to unite his country — is a story for the ages of enormous power.”

S.C. Gov. Nikki Haley also praised Mandela on Thursday.

“There are no words to describe the impact Nelson Mandela had not just on his country but on the world,” Haley said in a statement. “May we all continue to learn from his courage, his grace, and his incomparable strength.”