Born in Richmond, state capital of Virginia, he was brought up in nearby Roanoke. Hill's father, an alcoholic, abandoned him and he was brought up by his grandparents until he was reunited with his mother, who had married again. In high school, he was shocked to find that there was no law against lynching. A family member gave him an annotated copy of the US constitution, and he discovered the supreme court's 1896 decision, in Plessy v Ferguson, that segregation was legal.
Hill set out to change that injustice. "I went to law school," he said later, "so I could go out and fight segregation." He came under the influence of the great law teacher Charles Hamilton Houston and, in 1933, he graduated second in his class. First in the class ahead of him was his friend Thurgood Marshall, who went on to argue the Brown case before the supreme court and was appointed by President Lyndon Johnson as the first African-American justice on the court.
Hill and a group of talented Howard law graduates, including Marshall worked with the National Association for the Advancement of Colored People and its legal defence fund on a whole series of civil rights cases.
Their strategy was based on using the law as a tool for social and racial change. They argued that education should be their priority, and that legal education was the highest priority of all. They believed that US lawyers would find it hard to deny that fairness demanded that black law students should go to the same law schools as whites. Houston's perception, Hill recalled, was that "We ought to ... challenge 'separate but equal' at its weakest point - and that was the inequality. Everything was separate but nothing was equal."
Hill went on to practise law in Roanoke and then in Richmond, where he was later the first African-American elected to the city council since the reconstruction era after the civil war. He won a key decision in a Norfolk, Virginia, case that pay for black and white teachers must be equal.
In 1943 he joined the army, and came back from Europe more determined than ever to work for desegregation. He was telephoned in 1951 by a young woman who told him that her rural high-school class in Farmville, near Richmond, was going on strike against her school's rundown premises. Hill took the case, which became a leading civil rights case as Davis v County school board of Prince Edward county. This was one of the four cases that were merged with Brown - a case from Topeka, Kansas - into the historic judgment.
Hill was blind and in a wheelchair in the last years of his life, but he remained committed to the struggle for equality. In a late interview he said that the "pursuit of happiness" mentioned in the Declaration of Independence "ought to include the right to be taught and trained, to be able to do something constructive, to move toward a civilised society. That's what I believe in. I'm an advocate for social change."
He also maintained that the civil rights struggle would not have been possible without the legal victories won by himself and his friends. In 1999 he was awarded the presidential medal of freedom, America's highest civilian award, by President Bill Clinton. He is survived by his son.
· Oliver White Hill, lawyer, born May 1 1907; died August 5 2007
· The article above was amended on Wednesday August 8 2007. The US supreme court decision on racial segregation in the Plessy v Ferguson case was given in 1896, not 1895. This has been changed.