Mildred Loving, a black woman whose anger over being banished from Virginia for marrying a white man led to a landmark Supreme Court ruling overturning state miscegenation laws, died Friday at her home in Central Point, Va. She was 68.

Peggy Fortune, her daughter, said the cause was pneumonia.

The Supreme Court ruling, in 1967, struck down the last group of segregation laws to remain on the books -- those requiring separation of the races in marriage. The ruling was unanimous, its opinion written by Chief Justice Earl Warren, who in 1954 wrote the court's opinion in Brown v. Board of Education, declaring segregated public schools unconstitutional.

In Loving v. Virginia, Warren wrote that miscegenation laws violated the Constitution's equal protection clause. "We have consistently denied the constitutionality of measures which restrict the rights of citizens on account of race," he said.

By their own widely reported accounts, Loving and her husband, Richard, were in bed in their modest house in Central Point in the early morning of July 11, 1958, five weeks after their wedding, when the county sheriff and two deputies, acting on an anonymous tip, burst into their bedroom and shined flashlights in their eyes. A threatening voice demanded, "Who is this woman you're sleeping with?"

Loving answered, "I'm his wife."

Richard Loving pointed to the couple's marriage certificate hung on the bedroom wall. The sheriff responded, "That's no good here." The certificate was from Washington, D.C., and under Virginia law, a marriage between people of different races performed outside Virginia was invalid. At the time, it was one of 16 states that barred marriages between races.

After Richard Loving spent a night in jail and his wife several more, the couple pleaded guilty to violating the Virginia law, the Racial Integrity Act. Under a plea bargain, their one-year prison sentences were suspended on the condition that they leave Virginia and not return together or at the same time for 25 years.

Judge Leon M. Bazile, in language Warren would recall, said that if God had meant for whites and blacks to mix, he would have not placed them on different continents. Bazile reminded the defendants that "as long as you live you will be known as a felon."

They moved to Washington and had three children. They returned home occasionally, never together. But the Lovings missed family, friends and their easy country lifestyle in the rolling Virginia hills.

By 1963, Mildred Loving could stand the ostracism no longer. Inspired by the civil rights movement and its march on Washington, she wrote Attorney General Robert F. Kennedy and asked for help. He wrote her back, and referred her to the American Civil Liberties Union.

The ACLU took the case.