Now the documentary, Cruel and Unusual, tells their stories, with its English filmmakers fundraising to get it screened in New York and Los Angeles so it can qualify for Oscar consideration.
Thrown into solitary and forgotten
It's hard to believe that three men could spend so long jailed in such inhumane conditions, for a murder they didn't commit, but that's what happened to the "Angola 3".
The men were originally sent to Angola Prison in 1971 on other charges, but when Miller was killed, the men were targeted as Black Panther Party members, framed and forgotten, consigned to cells measuring 1.8 metres by 2.7 metres.
Woodfox and Wallace were convicted of the murder. King was said by authorities to be linked, but wasn't charged, reports say. They threw him in solitary anyway.
That was 1972.
It would be a quarter of a century - 1997 - before a former Black Panther Party member Malik Rahim and a law student named Scott Fleming would discover the three were still in solitary.
Finally, the questions about their original trials, the appeals, and the exposure of their treatment in solitary confinement - whatever they had done - began.
The case brought against them fell apart with the discovery of tarnished eye witness statements, lost DNA evidence and alleged misconduct by the prosecutors.
By now their plight had gained international attention. Amnesty International and a swag of other organisations campaigned for their release.
Robert King: 'We were caged up"
King was released in 2001 when the court reversed his conviction, following 29 years in solitary confinement, and he pleaded guilty to a lesser charge.
He spent almost three decades glimpsing the outside world through a tiny window from his cell, longing for the few hours a week he might feel the sun on his face, he told The Guardian in 2015.
"We were caged up," he told the publication.
"I don't think a person can go through that and come up unscathed."
Reflecting on his time in solitary, King said he was shackled hand and foot whenever he was out of his cell. He could see and talk with a few of the other prisoners, but they had to be careful not to talk too loud, or they'd be "written up".
Initially, there was no windows and no time outside. Eventually, he was allowed a few hours a week outdoors, and given a cell with a window.
When asked how he didn't go crazy, he replied, laughing, "I didn't say I wasn't crazy."
"It was bitter," he said. "But there are some things that you can make out of lemons. I just tried every day to make lemonade."
King has been instrumental in the making of Cruel an Unusual, a project which took eight years.
In the years since his release, King has written a book, has become a prison reform activist and often gives talks on his experiences.
"I can tell you from experience: If you've done time in solitary confinement, you've been damaged. Even if you survive it, it has an impact on you," he told a recent conference.
Herman Wallace: Cruel Twist
Wallace spent 41 long years in solitary, and authorities fought his release to the very end.
After being in solitary confinement for 41 years, Wallace had developed advanced liver cancer.
A district court judge threatened to hold the state in contempt, and ordered his release to a hospital on October 1, 2013. Wallace died three later, on October 4, 2013.
Albert Woodfox: "I would not let them break me"
Woodfox continued to protest his innocence as holes in the cases continued to shock.
He said one eyewitness in the case who claimed to have seen him commit the murder was later revealed to have been blind
In 2014, judges upheld unanimously that his conviction had been secured as a result of racial discrimination.
He eventually entered a plea on a lesser charge and was finally released in February, 2016, after 43 years waiting for justice in a shoebox cell with a concrete bunk a metal toilet and bars on the front. At least, he said, he could hear other prisoners.
He is now 69 years old. He was in isolation for longer than any of American prisoner.
Five months after his release he went to Harlem, the place, he told The New Yorker, where during his last week of freedom, he met members of the Black Panther Party for the first time.
It was, he said, "the first time I'd ever seen black folk who were not afraid".
Asked how he remained sane in solitary, he told The Guardian in his first interview as a free man he made a "conscious decision", way back in 1972, that he would survive, and the Angola 3 made a vow to be strong.
"We made a conscious decision that we would never become institutionalised," he said.
"As the years went by, we made efforts to improve and motivate ourselves," he said.
"I promised myself that I would not let them break me, not let them drive me insane."
He read newspapers and magazines for at least two hours daily. Watched news reports and documentaries on the small TV he was allowed.
He counted himself lucky to be able to read and write. But it didn't mean he was spared claustrophobia and panic attacks. Sometimes the claustrophobia was so bad, he'd lean his mattress against the wall, wrap himself in a blanket and sleep sitting up.
He was in his cell 23 hours a day. The other hour he'd spend in the concrete box called the exercise yard. He'd walk around it, shackled, on his own.
He is now using the time he has left to end solitary confinement in America.
I get apprehensive when somebody asks me something I can't answer, like 'What does it feel like to be free?'" he told The New Yorker.
"How do you want me to know how it feels to be free? Ask me in twenty years."
