"When I met Cecil B. Moore, he showed me a different strategy of how to deal with things," he said. "We're talking about civil rights, human rights, picketing, and going to jail. We were nonviolent, but Cecil would tell you, 'If anybody hits you, knock their ass out.' "
Mr. Dorn was born in Philadelphia on Jan. 5, 1945, the son of Leander and Bessie Dorn.
He was raised in North Philadelphia and attended Thomas Edison High School. He was married and divorced twice. As were many young black men in the 1960s, Mr. Dorn was drawn to the growing civil rights movement.
As a teen, he was one of a group of young activists known as the Cecil B. Moore Philadelphia Freedom Fighters. Among its members were Ken "Freedom Smitty" Salaam, Karen Asper-Jordan, Richard Watson, Eugene "Tree" Dawkins, and Bernice Mills-DeVaugn.
With Moore, they focused much of their efforts on Girard College, whose founder, Stephen Girard, specified in his will that the school, behind high stone walls in north-central Philadelphia, was for white male orphans.
That policy sparked protests that in 1965 included visits by King. In 1968, the U.S. Supreme Court let stand a court ruling allowing black boys to go to the school. Girls were admitted in the 1980s.
Mr. Dorn held many jobs over the years and was most recently a concert promoter, but he always focused on civil rights and helping people in need.
He went back to Girard on several occasions to talk to students there about the civil rights movement and the school's history.
He said the disc jockey Georgie Woods introduced him to King in the early 1960s. On King's visits to Philadelphia, Mr. Dorn often served as his driver.
He recalled King as "such a low-key type of individual." Mr. Dorn remembered King's saying, "I'm a servant. And if I work harder, I will be a bigger servant. . . . I never chose to be a leader."
Asper-Jordan said Mr. Dorn could be forceful yet easygoing.
"He was a lion, but he was a gentleman at the same time," Asper-Jordan said. "He did not back down. Somebody called him a pit bull, but he was a gentleman, and he loved children."
Diane Turner, curator of the Charles L. Blockson Afro-American Collection at Temple University, said Mr. Dorn remained an activist throughout his life, noting that he was a leader in the successful 2012 effort to have SEPTA put Cecil B. Moore's full name on the buses that run on the avenue named in his honor.
Mr. Dorn also would help to get homeless people off the street and into shelters when the city issued a "Code Blue" because of extreme cold weather, his brother Kelvin said.
"He was passionate about people. Helping people and caring for people, that was his passion," his brother said.
In addition to his brother, Mr. Dorn is survived by sons Solomon and Barry; daughters Melvina and Trina; three brothers; and two sisters. Memorial services were pending.