"Do not give up," Mfume said Mandela wrote him from prison, where he had somehow read about the councilman's efforts in the 1980s to get the city to divest from companies that did business with the apartheid government of South Africa. The two had never met, although Mfume had been agitating for his release since his student days at Morgan State University.
"I thought, I should be telling him not to give up," said Mfume, who would ultimately be elected to Congress and in 1994 attended Mandela's inauguration as president of the country that once imprisoned him. "That touched me in a way I can't even explain."
Throughout Maryland as elsewhere, Mandela's death Thursday prompted many to reflect on how his words and actions inspired them.
Maryland Del. Sandy Rosenberg, who long fought for the repeal of the state's death penalty, frequently quotes something Mandela said in 1994 when he established his country's first Constitutional Court, which replaced the apartheid government's previous judicial system.
"The last time I was in court," Mandela said, "was to hear whether or not I was going to be sentenced to death."
For Rosenberg, a Baltimore Democrat, the words distilled why he opposed capital punishment. "Here was a living example to the world of someone who had faced the possibility of the death penalty," Rosenberg said. "To have it be someone of such a stellar character makes the point: It's inappropriate, it's wrong, for the state to execute one of its own citizens.
"For me at least ... you gasp. You're aghast. If a Mandela could come this close to facing the prospect of execution, so could someone else we'll find out later is innocent."
Rosenberg would see his work pay off this year, when the General Assembly repealed the death penalty. Coincidentally, on the day Mandela died, Rosenberg said he happened to write a former law professor to tell him of his role in repealing capital punishment.
"It was the most profound thing I will ever do," Rosenberg said.
When Mandela was sworn in as his country's first democratically elected president, Mfume and Baltimore Mayor Kurt L. Schmoke were among the official U.S. delegation.
The experience was even more personal for Schmoke because of a familial tie, and tragedy: Schmoke's brother Alex had been teaching at a school outside Pretoria when he was killed in a car accident about four months before the inauguration.
Schmoke had worked with officials to bring his brother's body back to the U.S., when the White House called to invite him to join the delegation to Mandela's inauguration.
"On the night before the inauguration, there was an event where members of the delegation mentioned Alex, and I talked with everybody about that," Schmoke said. "It was a very emotional and moving moment for me."
A former dean of Howard University School of Law in Washington, Schmoke is now the school's interim provost and chief academic officer as well as its vice president and general counsel. He said he still visits South Africa regularly, because the law school has a summer program at the University of the Western Cape in Cape Town.
Schmoke said Friday that he remembered how the inauguration drew world leaders from opposite sides of the political spectrum who were eager to meet in the middle. "There were leaders who disagreed with one another on every possible policy issue," he said.
He recalled a moment when former South African President F.W. De Klerk, who brokered the end to apartheid, was on stage and Cuban leader Fidel Castro arrived with a large entourage. "The crowd gave Castro this enormous ovation, and he went up on stage," Schmoke said.
"There you had a rabid anti-Communist and one of the leaders of international communism, but for that day they came together for praise of Mandela and a new South Africa," Schmoke said.
After Mandela spoke, a stirring flyover of jets provided a visual reminder of the change that Mandela represented.
"Their Air Force jets let out streams with the colors of the new South African flag," Schmoke said. "It was quite amazing, and a new moment for the country."