For Norma McCorvey, it was just a minor setback in an existence plagued by tragedy, but for millions more it was a defining moment, not only in their lives, but in U.S. history.

She was 22, unmarried and five months pregnant with her third child in 1970. She simply wanted a quick abortion, but her two female lawyers had other ideas: they were intent on using her to establish a constitutional right to have an abortion, challenging Texas laws that prohibited terminations except when a mother’s life was at risk.

In the process, with Norma maintaining her anonymity under the pseudonym of Jane Roe, they ushered in the landmark 1973 court decision of Roe vs Wade that legalised abortion in America.

Campaigning for abortion: Pictured in April 1989, Norma McCorvey (left) with attorney Gloria Allred (right) in front of the US Supreme Court in Washington,DC

On Saturday, the woman who set in train the most famous and contentious Supreme Court decision in its history died, aged 69, in Katy, Texas. Norma was living at an assisted living home when she died of heart failure.

Depending on where you stand on abortion, Norma McCorvey either saved generations of women from lives blighted by unwanted offspring, or she paved the way for the legal destruction of perhaps 58 million children.

That brutally polarised view of Roe vs Wade is, astonishingly, mirrored in her own confused, contradictory life — one that saw her go from being a pro-abortion crusader to being a born-again Christian and anti-abortion firebrand who fiercely preached the exact opposite of what she’d helped create a few years earlier.

For that reason, Ms McCorvey became a pawn for both sides in a battle so ferocious in the U.S. (which legalised abortion six years after the UK did in 1967) that doctors are still sometimes killed for providing late-term terminations.

In a 1994 book, I Am Roe: My Life, Roe v. Wade, And Freedom Of Choice, she wrote: ‘I wasn’t the wrong person to become Jane Roe. I wasn’t the right person to become Jane Roe. I was just the person who became Jane Roe, of Roe v. Wade. And my life story, warts and all, was a little piece of history.’

Hers was actually a large piece of history. In disallowing many state and federal restrictions on abortion, the case sparked a national debate that is never likely to die down. Even more than 40 years after her court case, any threat to the Roe vs Wade decision is enough to provoke fury from pro-choice campaigners across the U.S. — as it did when Donald Trump was elected president.

And later campaigning against abortion: Norma pictured in 1997 standing with nine-year-old Meredith Champion

Anxious to win the Bible Belt vote, in his campaign Mr Trump rowed back on his previous liberal New York values and declared his opposition to abortion.

The huge significance of his view became clear when he was able to nominate a conservative judge to fill the vacant ninth seat in the U.S. Supreme Court. If, as expected, he is able to nominate more judges, a conservative majority in the court could, in theory, overturn Roe vs Wade.

Her case has gone into popular mythology, but the woman at its centre was deeply troubled.

Born Norma Nelson in a small town in Louisiana, Norma’s father, a TV repairman, walked out on the family when she was young. She and her older brother were raised by her mother, Mildred, a violent alcoholic. Aged ten, Norma stole money from a petrol station cash register and absconded with a female friend to Oklahoma, where they tricked hotel staff into renting them a room.

Handed in to the police, she was declared a ward of the Texas state and sent to a reform school for troubled girls. Released at 15, she lived with her mother’s cousin, whom she claimed raped her every night for three weeks. By 16, she’d married a sheet-metal worker named Woody McCorvey, who beat her. She left him within months and their baby, Melissa, was adopted — by her mother.

Norma descended into drugs and drink — addictions which she said lasted for the next 30 years. She had another daughter, Paige, in 1967, who was also adopted.

Norma and her attorney Gloria Allred hold hands as they leave the Supreme Court building in Washington after sitting in while the court listened to arguments in a Missouri abortion case

A casual fling two years later produced her third, and by far most momentous, pregnancy. At the time, Ms McCorvey was working in a circus. She spent part of the time living with her father, and the rest living on the streets.

Even after she later became an ardent anti-abortionist, she always defended her reason for wanting to terminate her third pregnancy. ‘I didn’t want to bring a baby into the world I was living in,’ she said years later. ‘I never knew where I was going to sleep at night. I never knew if I was going to eat.’

Abortion was illegal in Texas but the idea of a visit to a back-street abortion clinic horrified her.

Too poor to travel to a state where abortion was legal, she was the perfect client for the young, idealistic lawyers, Sarah Weddingtion and Linda Coffee, who wanted to challenge the Texas abortion ban on the grounds it violated a woman’s constitutional right to privacy in her reproductive choices. Ms McCorvey claimed the pregnancy was the result of a gang rape, but later admitted she had lied to strengthen her case for an abortion — the rape claim wasn’t mentioned in her lawsuit.

In one of many ironies about her life, her victory — by a seven to two vote in the Supreme Court — came too late for her. She’d had the baby three years earlier.

Gloria and Norma (right) during a Pro Choice Rally on July 4, 1989 in Burbank, California

She claimed the epic legal battle went ‘right over’ her head. Drifting back to the bottle, she sank into ‘deep depression’.

It took her around seven years to start embracing her new-found fame and notoriety. From 1980, she began to attend pro-abortion rallies and working in abortion clinics. Happy to reveal she was Jane Roe, she started to get hate mail calling her a ‘baby killer’.

Body parts of ripped up baby dolls were scattered on her lawn. One night, a man fired a shotgun from a passing lorry, shattering her windows.

But more subtle tactics were what turned her against abortion. Operation Rescue, an anti-abortion group trying to reverse Roe vs Wade, rented a house next door to the abortion clinic where Ms McCorvey worked.

On Saturday Norma McCorvey died, aged 69, in Katy, Texas

Its members befriended her, buying her lunch and slowly turning her to their point of view. She described her conversion as she sat looking at a poster showing foetal development in their office.

‘The [baby’s] progression was so obvious, the eyes were so sweet,’ she said. ‘It hurt my heart, just looking at them. I ran outside and finally it dawned on me. “Norma”, I said to myself, “They’re right”.’

Then in 1995, she was baptised and in one of the most dramatic U-turns imaginable, moved out of the clinic and into the anti-abortion HQ next door.

She spent the last years of her life gathering testimonies from women who say that having an abortion ruined their life. Ms McCorvey — who never had one herself — wanted the evidence to be presented to the Supreme Court when it was needed.

Just as she once led pro-choice rallies, she became a stalwart at pro-life ones. In 2009, she was arrested in a Catholic university in Indiana, protesting against a visit by President Obama, whom she described as a ‘child killer’ over his support for abortion rights.

Even with Roe vs Wade in place, pro-choice activists claim the battle is far from won. Conservative states have introduced restrictions, such as banning abortion in cases where the baby’s heartbeat can be heard, or forcing mothers to undergo an ultrasound.

In 2009, a late-abortion doctor, George Tiller, was shot dead by an anti-abortion extremist. Norma McCorvey insisted the killer went too far, even though Dr Tiller ‘was a monster’.

What an irony that the woman who gave others control of their bodies should depart this world just as a president who is now vociferously pro-life could re-open one of the most contentious debates in American society.