“Mr. Cohen, tell the Court I love my wife and it is just unfair that I can’t live with her in Virginia.” That was the message that Bernard S. Cohen delivered in 1967 to the justices of the U.S. Supreme Court on behalf of his client, Richard Loving, a White man who had been roused from his bed in the middle of the night and arrested along with his wife for violating a state ban on interracial marriage.

Richard Loving and Mildred Loving, who was of African American and American Indian heritage, became the protagonists in a legal battle that ended with a ruling striking down anti-miscegenation laws — “the last de jure vestige of racism” in the United States, as Mr. Cohen later described them. Less than seven years out of law school, he was one of two lawyers to argue their case before the Supreme Court, shaping an argument that would reverberate for decades in that chamber and beyond.

Mr. Cohen, who later became a prominent liberal member of the Virginia House of Delegates, died Oct. 12 at an assisted-living facility in Fredericksburg, Va. He was 86. The cause was Parkinson’s disease, according to his family.

Mr. Cohen joking described himself as “an old man of 29” when he first met the Lovings, a couple from Caroline County, roughly midway between Fredericksburg and Richmond, where both had grown up. Richard, a bricklayer, was 24 when they married in 1958. Mildred, six years his junior, was pregnant with the first of their three children.

Prohibited by the Racial Integrity Act of 1924 from marrying in Virginia, the couple were wed in D.C. on June 2, 1958. Weeks later, after their return to Virginia, local authorities forcibly entered their home at 2 a.m., shining flashlights in their eyes.

“They asked Richard who was that woman he was sleeping with, and I said, ‘I’m his wife,’ ” Mildred Loving later recalled, according to an account in Washingtonian magazine.

“Not here you’re not,” the sheriff replied.