The old saying holds that history is written by the winners.

A new book explores the life of U.S. Supreme Court Justice John Marshall Harlan, who, through his writing, made history even though he lost. Harlan was on the court in 1896 when it endorsed racial segregation in Plessy v. Ferguson and was the lone justice who voted no. He wrote the only dissenting opinion.

"His dissent was largely invisible in the white community, but it was read aloud in Black churches. It was published in Black newspapers. This was the one link of hope that white people might support them and see the law through their eyes," said Peter Canellos, author of The Great Dissenter: The Story of John Marshall Harlan, America's Judicial Hero, in an interview on Morning Edition.

It took generations, but eventually the dissenter won. The court ruled differently in 1954.

Harlan, a white man from Kentucky, grew up before the Civil War in a family that enslaved people.

"One of the great mysteries of Harlan's career is that he grew up in such a family and yet became the leading defender of Black rights of his generation," Canellos. Part of the reason might have been a Black man who grew up with him, widely believed to have been his half-brother.

Interview Highlights

On Harlan writing dissents during the era of Jim Crowe

That's what's striking about it. I think the court of that period has gotten way too little attention in history because it was responsible, essentially, for segregation and clearing the way for segregation. That court ... ruled against civil rights, it ruled against voting rights for African Americans. In Plessy v. Ferguson it approved the legal architecture of segregation. As Harlan predicted in his dissent in Plessy v. Ferguson, it consigned the nation to hundreds of years of racial strife. He says in that dissent, what can more surely sow the seeds of racial discord than a system under the law that creates two separate systems of rights, one for Blacks and one for whites?

On how Harlan and the court's majority could find support in the Constitution and law to bolster very different conclusions regarding separate but equal

I think it's not too mysterious. I hate to say it, but I think notions of white supremacy, prejudice and — frankly — expediency are very visible in the majority opinion of Plessy v. Ferguson. You go back in these cases and you try to say, well, could this be an issue in which reasonable jurists might disagree? And the answer essentially is no in Plessy v. Ferguson. The majority opinion is an abomination. The key line in the majority opinion says this is a law that was specifically enacted to put Black people in a separate [train] carriage, and they said if there's any stigma here it's because Black people themselves are putting that construction on it. Harlan's dissent, which was forceful, essentially called their bluff on everything. He noted the plain language of the Constitution, which said equal protection under law in the 14th amendment is the law of the land. And Harlan didn't just call them out on the law. He issued kind of a manifesto that went to the real heart and soul of what the law is and what the Constitution means in this country. And I think his dissent in Plessy v. Ferguson is one of the great documents in American history.

On what it's like to go through historical cases at a time when judges, justices and the Supreme Court have been in the news

I think it suggests the parallels between that era and this era. We may well be entering a period when the Supreme Court is far more conservative than the country. That's what happened in the 1880s and 1890s. There was a long string of pro-business presidents of both parties that appointed Northern railroad attorneys essentially to the Supreme Court, and then you have this economic crisis and this racial crisis, and they're not equipped to deal with it. We had the wrong people on the Supreme Court, and they set the country back decades. I hope that doesn't happen, and there's certainly a lot of history in the Supreme Court to suggest that justices who are appointed with one set of expectations end up completely defying them. So that may well happen this time. But we may also be entering a period where, as Ruth Bader Ginsburg suggested, dissent is every bit as important as the majority opinion — where today's justices who dissent on cases will be the Harlans of the next generation.

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