When Charleston fell and Confederate troops evacuated the badly damaged city, freed slaves remained. One of the first things those emancipated men and women did was to give the fallen Union prisoners a proper burial. They exhumed the mass grave and reinterred the bodies in a new cemetery with a tall whitewashed fence inscribed with the words: “Martyrs of the Race Course.”

And then on May 1, 1865, something even more extraordinary happened. According to two reports that Blight found in The New York Tribune and The Charleston Courier, a crowd of 10,000 people, mostly freed slaves with some white missionaries, staged a parade around the race track. Three thousand black schoolchildren carried bouquets of flowers and sang “John Brown’s Body.” Members of the famed 54th Massachusetts and other black Union regiments were in attendance and performed double-time marches. Black ministers recited verses from the Bible.

If the news reports are accurate, the 1865 gathering at the Charleston race track would be the earliest Memorial Day commemoration on record. Blight excitedly called the Avery Institute of Afro-American History and Culture at the College of Charleston, looking for more information on the historic event.

“‘I’ve never heard of it,’ they told me,” says Blight. “‘This never happened.’”

But it was clear from the newspaper reports that a Memorial Day observance was organized by freed slaves in Charleston at least a year before other U.S. cities and three years before the first national observance. How had been lost to history for over a century?

“This was a story that had really been suppressed both in the local memory and certainly the national memory,” says Blight. “But nobody who had witnessed it could ever have forgotten it.”