Shelia Washington was cleaning her parents’ room at their home in Scottsboro, Ala., in the 1970s when she discovered a paperback book hidden in a pillowcase underneath the bed.

The book, “Scottsboro Boy” (1950), was a harrowing memoir by Haywood Patterson, written with the journalist Earl Conrad, about Mr. Patterson’s experience as one of nine Black youths who were falsely accused of raping two white women in 1931 in a notorious miscarriage of justice in the Jim Crow South, one that set off an international outcry at the time.

Ms. Washington, then 17, started to read the book, but her stepfather, who owned it, took it away, saying it was too horrific for children. In time, she did read it, and the story seared her soul, she said. She vowed to do something about it.

“I said, ‘One day, when I get older, I’m going to find a place and honor the Scottsboro Boys and put this book on a table and burn a candle in their memory,’” she told NPR in 2020.

It took her decades, but she accomplished her goal, and more. She became the catalyst behind the creation of the Scottsboro Boys Museum and Cultural Center and then won something few thought possible — not only posthumous pardons for the defendants but also full exonerations for the history books.

Ms. Washington was 61 when she died on Jan. 29 at a hospital in Huntsville. Loretta Tolliver, a cousin and board member of the museum, said the cause was a heart attack.

Ms. Washington saw that the story of the Scottsboro Boys had helped fuel the civil rights movement decades later, and she was determined that it be recognized.

The nine young men, all under 20, were riding a Southern Railroad freight train in March 1931, most of them looking for work in the depths of the Depression and most not knowing one another, when they got into a brawl with some white hoboes who had hopped the same train.

The police arrested the Black youths on a minor charge. But when deputies questioned two white women who had been on the train, the women accused the boys of raping them. Accounts differ, but the women were facing their own charges of vagrancy and illegal sexual activity stemming from an unrelated incident and apparently thought that by accusing the boys they could avoid being arrested themselves.

The defendants were all tried swiftly in separate trials in Scottsboro, a small city on the banks of Guntersville Lake in northeastern Alabama, and attracted widespread attention; by her account, Harper Lee later drew on the case as inspiration for “To Kill a Mockingbird.”

All-white juries in Scottsboro convicted each of the youths, and all but the youngest of the nine were sentenced to death. After appeals, the U.S. Supreme Court overturned the convictions, which led to more appeals, trials and retrials. Along the way, one of the white women, Ruby Bates, recanted her story, but the defendants remained behind bars.

The cases led to two landmark Supreme Court civil rights rulings — one that opened the door to allowing African Americans to serve on juries, the other ensuring that defendants had the right to adequate legal representation.

The sentences were eventually reduced or dropped entirely, and the defendants were freed; most of them had been incarcerated on and off for several years. But they were not declared innocent, and their names were not cleared.