Speaking in March 1968 before Local 1199, the powerful Service Employees International Union, of health-care workers in New York City, Martin Luther King, Jr. declared at one point, using one of the many great phrases and insights that fill his speeches, that "the arc of the moral universe is long, but it bends toward justice."

Black Americans have long had graphic evidence that the arc of the moral universe�the time it takes American society to right great wrongs, to redress injustice�can be long indeed. They have had to be, and have been, very patient in their hope that ultimately justice will prevail, and in their determination to see that it does.

Nothing more poignantly illustrates that reality than the pursuit of the still-unsolved racist murders of the civil rights era of the 1950s and 1960s. Since 1989 prosecutors in the Deep South have re-examined 19 killings of Blacks by whites that occurred during those years. Thus far, there have been seven convictions, one mistrial, and one acquittal.

And nothing more poignantly symbolizes the bittersweet temper of finally seeing justice done in these cases than the Birmingham Church Bombing case of September 15, 1963. The blast at the Sixteenth Street Baptist Church, a key staging ground for the civil rights demonstrations earlier that year that were a watershed for the entire civil rights movement, occurred on a Sunday morning as Sunday school was being held. It killed four adolescent girls and injured 22 other people in the church.

On May 1, Thomas E. Blanton, Jr., 62, was convicted of murder for the bombing by a Birmingham jury, the second of four original suspects to be convicted for the crime. He had been free for nearly 38 years after the bombing and for 24 years after state prosecutors had concluded they didn�t have enough evidence to charge him.

After the verdict was read, Doug Jones, the United States attorney for Birmingham, who prosecuted the case, walked to the courtroom gallery and exchanged long, emotional hugs with Chris and Maxine McNair, whose daughter, Denise, was the youngest of those killed.

But, as the New York Times report put it, "an eerie quiet hung in the courtroom for several minutes, as if everyone present was afraid to shatter the solemnity."

The McNairs, who have rarely spoken about their daughter�s death, declined to comment on the verdict.

Part of the pain must be in knowing that not only are there savages who will do such things, but knowing that those who do were, apparently, deliberately protected by some law officials for years.

That belief, which has long been widespread in the civil rights community, was provoked after the trial by an extraordinary op-ed piece in the Times about the role of the Federal Bureau of Investigation in the early years of the case.

The article was written by Bill Baxley, the former Alabama attorney general, who in 1971 courageously re-opened the investigation into the bombing. It was Mr. Baxley�s prosecution of Robert "Dynamite Bob" Chambliss, the leader of the murderers, which resulted in his conviction in 1977 and life sentence (Chambliss, still unrepentant, died in prison in 1985).

Mr. Baxley, in a bitter tone, declared that at that time the agency�s high command deliberately "held back" secretly made tape recordings of the suspects, which, in his view, proved their involvement in the bombing.

"After we were repeatedly stonewalled," Baxley writes, "my faith in the integrity of the F.B.I. dissipated. What had at first seemed an innocent bureaucratic shuffle was revealed to be a charade� . I do know that rank-and-file F.B.I. agents working with us were conscientious and championed our cause. The disgust I feel is for those in higher places who did nothing."

That stonewalling has meant that several of those suspected of participating in the crime will never be brought to justice, and the long wait for justice remains a bitter thing for many to contemplate.

Still, it is worth noting that those determined to see justice done, in Birmingham and elsewhere in the South, now include a more significant number of whites. Their involvement in the effort indicates that the racial callousness and brutality of the past produced in them, too, a determination to do what they could to contribute to the righting of great wrongs.

But, realizing that the arc of the moral universe is long, we can celebrate the words of Alpha A. Robertson, 82, who along with the McNairs, is the only surviving parent of one of the girls killed in the church. She said, "I�m very happy that justice came down today, and, you know, that�s enough, isn�t it? You know, I didn�t know if it would come in my lifetime."

As Doug Jones, the United States attorney, said in his summation to the jury, "It�s never too late. It�s never too late for the truth to be told. It is never too late for wounds to heal. It is never too late for a man to be held accountable for his crimes. It is never too late for justice."

Later, amid the celebration of the verdict on the steps of the courthouse, Mr. Jones, speaking to reporters, added, "They say that justice delayed is justice denied, [but], folks, I don�t believe it for a minute. Justice delayed is still justice, and we�ve got it here in Birmingham, Ala."

I�m sure Martin Luther King, Jr. is pleased.