American Supreme Court judge who recognised a woman's right to abortion in Roe v Wade

Harry Blackmun, the former American Supreme Court judge who has died aged 90, was best known for his ruling in the 1973 case of Roe v Wade, which for the first time recognised a woman's constitutional right to abortion; his judgment ignited one of America's most explosive political debates.

Blackmun's decision in the case relied on a controversial and broad interpretation of the Constitution. Based on a woman's "right to privacy", he found that an expectant mother had the right to abortion in the first three months of her pregnancy.

The decision of Blackmun's court - a 7-2 majority - was welcomed by liberals but vilified by conservatives. For the rest of his life, Blackmun was subjected to death threats by anti-abortionists. He received some 60,000 letters describing him as a murderer and butcher, and comparing him with the Nazi perpetrators of genocide. Blackmun insisted on reading all such mail, saying: "I want to know what the people who wrote [it] are thinking."

Subsequently, the Supreme Court came close on several occasions to reversing Roe v Wade. Blackmun warned that to do so would force "hundreds of thousands of women each year to defy the law" and to resort to the "unclean and unsympathetic hands of back-alley abortionists". "Every year," he argued, "many women, especially poor and minority women, would die or suffer debilitating trauma, all in the name of enforced morality or religious dictates or lack of compassion."

In 1992, a 5-4 Supreme Court majority reaffirmed his decision, but Blackmun cautioned that it would constitute good law only for as long as the composition of the present court remained unchanged.

Harry Andrew Blackmun was born on November 12 1908 at Nashville, Illinois, where his mother's family owned a flour mill. His father, a lawyer manque, was successively a fruit wholesaler, hardware store proprietor and insurance salesman. The family was devoutly Methodist.

Imbued with the Puritan work ethic, young Harry was serious and diligent - even, according to one of his classmates, "a teacher's pet". One of his closest schoolfriends was Warren Burger, who would become Chief Justice of the Supreme Court in 1969. The two did a newspaper round together.

Blackmun helped to fund his time at Harvard by working as a janitor and a tutor. After a BA in maths, he graduated from Harvard Law School in 1932 and was admitted to the Minnesota Bar.

He spent a year clerking for a judge before joining the Minneapolis law firm of Dorsey, Owen, Barker Scott & Barber. By 1943 he was a general partner, specialising in tax and wills. He also taught at the University of Minnesota Law School.

Blackmun became general counsel of the Mayo Clinic in Rochester, Minnesota, in 1950. Nine years later, President Eisenhower appointed him to the Eighth United States Circuit Court of Appeals. Blackmun's old schoolfriend Warren Burger - then a judge of the Washington DC Court of Appeals - was reportedly among his backers. The Eighth Circuit sits in St Louis, Missouri, and covers Arkansas, Iowa, Minnesota, Missouri, Nebraska and North and South Dakota.

Blackmun soon won respect for his scholarly and carefully drafted judgments. He established a reputation as a liberal in civil rights cases and as a conservative in criminal ones. One of his judgments led to the abandonment of the leather strap as a means of punishment in Arkansas schools; another promoted desegregation in schools and the reinstatement of dismissed black teachers.

Blackmun claimed to find decisions involving the death penalty "particularly excruciating", since he was not convinced of the propriety of capital punishment, or of its effectiveness as a deterrent. On retirement he would voice stronger opposition: "From this day forward, I shall no longer tinker with the machinery of death," he declared.

When President Richard Nixon appointed Blackmun to the Supreme Court in 1970, he hoped for a "strict constructionist" who would be inclined to apply the Constitution without indulging in innovative interpretation. The recently appointed Chief Justice Burger was such a man, and Nixon was candid about wanting to steer the Supreme Court in a more conservative direction. Conservative and liberal senators alike welcomed Blackmun's appointment, having rejected Nixon's first two choices.

On his appointment, Blackmun vowed to come to decisions based on the "definite and determined" meaning of the Constitution. He added, though, that that meaning was often "obscure".

If at the outset he was perceived as a safe conservative, by the time he retired in 1994, Blackmun was seen as the Supreme Court's most liberally-minded member. But he told friends that the court's politics had changed more than his own.

Blackmun tended to cast liberal votes in cases pitting individual liberties against governmental authority. When the court in 1993 ruled that American authorities need not give hearings before seizing and returning Haitians who had fled their homeland by boats, Blackmun was the lone dissenter.

"They demand only that the United States, land of refugees and guardian of freedom, cease forcibly driving them back to detention, abuse and death," he wrote. "That is a modest plea. We should not close our ears to it."

But generally he voted against expanding the rights of criminal suspects.

Physically slight, Blackmun was intense and somewhat reserved. But though softly spoken he was capable of passionate rhetoric in court. He used his spare time to attend sporting events - he could recite baseball batting averages and other athletics statistics - and to tend his garden.

Harry Blackmun married, in 1941, Dorothy Clark; they had three daughters.