Mwalimu Johnson, a prison-reform advocate and a sought-after counselor to thousands of fellow inmates, died Tuesday of kidney failure at his home in New Orleans. He was 78.

“Mwalimu was full of wisdom and knowledge that he gave out like he was handing out candy for Halloween. He will forever be with me,” said Norris Henderson, who got to know Johnson during 27 years Henderson spent at the Louisiana State Penitentiary at Angola on a wrongful murder conviction before he was released in 2003.

During the two decades Johnson served at Angola starting in 1977, he acted almost as the prison’s sage. “If you needed advice or counsel, you’d go to Ward 2 of the prison hospital and get all the wisdom you needed. All the guys did that,” said Calvin Duncan, who spent 28 years in Angola for a murder he didn’t commit before he was released in 2011.

Johnson stayed in the prison’s hospital because he was paralyzed and in a wheelchair, though few remember the chair slowing him down in any meaningful way. So, to see Johnson, prisoners first had to get a pass to the hospital, Henderson and Duncan said. But Johnson’s reputation for imparting good advice was such that neither one can remember a guard who refused to issue such a pass to a prisoner who requested it.

“That’s the weirdest thing about it,” Duncan said. “The institution knew it.”

Born Leonard Johnson in New Orleans, he was nicknamed “Micey” as a child and spent his early youth using and selling illegal drugs. Then, in 1958, he pleaded guilty to bank robbery and was sentenced to 15 years in Angola, which was then known as perhaps the bloodiest prison in the nation.

“That was part of the reason why he gave of himself as much as he did,” said his daughter, Nicole Hessier, now an investigator for the Orleans Parish Public Defenders Office. “He felt like he owed this debt for the wrong things he did as a younger man who had lacked knowledge or understanding.”

Influenced by their father’s experience, two of Hessier’s sisters also work in criminal justice: Lynthea Johnson Edwards works for the probation office, and Malaika Johnson is a defense attorney. Johnson’s fourth daughter, Mtamu Johnson, is a nurse.

Stories of Johnson’s efforts to establish peace in the prison are legendary — how he hated so much to see the inmates fight one another that he would walk into the middle of a knife fight to stop it. He spoke reasonably to frustrated, angry men who were known as rapists, saving many young men from sexual assaults, fellow prisoners said. “That’s how he earned his reputation, among guys that were gladiators back then,” Duncan said.

It also was then that Johnson, after studying Islam, chose the name Mwalimu, Swahili for “teacher.”

Johnson was released in the late 1960s but still had a mistrust of police. So, when a squad car drove up as he stood in the front yard of a relative’s house in 1975, he ran; he was shot in the back and paralyzed.

He was then sentenced to seven years for assault on the officers who had shot him and to 50 years for an unrelated armed robbery that he said he had nothing to do with. He would eventually be released for a wrongful sentence, but not until 1997 — more than 20 years later.

Soon afterward, Denny LeBoeuf hired him to answer the phones at the Capital Post-Conviction Project of Louisiana. “He had a magical way of dealing with the guys on death row,” said LeBoeuf, who would marvel to see young men burst into the office, often with families in tow. They would bear-hug Johnson and then tell their families, “This is the man who made my life possible.”

LeBoeuf’s successor, Gary Clements, heard the news about Johnson’s death as he drove to Angola, but many of the inmates already knew, having heard from guards who were equally heartbroken at the news, he said.

Johnson did the same for him, said John Thompson, who was a discipline problem at the prison for some of the time he spent on death row for a wrongful murder conviction. “When I would get out of the hole, Mwalimu would say, ‘When you gonna stop that? You can’t win that war.’ ”

Johnson urged Thompson to quit rebelling and to fight his battles in court, advice Thompson heeded. “That was my No. 1 adviser,” Thompson said.

Hessier recalled her childhood correspondence with her father, who was paralyzed and put back in prison when she was in grade school. He would correct the grammar or the math in her letters. He would write about cultural history or life.

“When I told him we were studying (the 18th century African-American poet) Phillis Wheatley in school, he wrote back a whole page about Phillis Wheatley,” she said.

He lived the name he’d chosen, she said: “He was a perpetual teacher.”

In addition to his daughters, Johnson is survived by four of his nine siblings — Althea, Lester Jr., Felton and Alvin Johnson — along with 19 grandchildren and three great-grandchildren.

Visitation will start at 10 a.m. Monday with a memorial service at 11 a.m. at the Charbonnet-Labat-Glapion Funeral Home, 1615 St. Philip St., New Orleans. Interment will be in Providence Park Cemetery in Metairie.