The scholar David Blight on his research into the one of the earliest, large memorial day commemorations. This took place in Charleston, SC, by newly liberated black Americans burying and honoring the Union dead. This history was later erased by white elites.
The largest of these events, forgotten until I had some extraordinary luck in an archive at Harvard, took place on May 1, 1865. During the final year of the war, the Confederates had converted the city’s Washington Race Course and Jockey Club into an outdoor prison. Union captives were kept in horrible conditions in the interior of the track; at least 257 died of disease and were hastily buried in a mass grave behind the grandstand.
After the Confederate evacuation of Charleston black workmen went to the site, reburied the Union dead properly, and built a high fence around the cemetery. …The procession was led by 3,000 black schoolchildren carrying armloads of roses and singing the Union marching song “John Brown’s Body.” Several hundred black women followed with baskets of flowers, wreaths and crosses. Then came black men marching in cadence, followed by contingents of Union infantrymen. Within the cemetery enclosure a black children’s choir sang “We’ll Rally Around the Flag,” the “Star-Spangled Banner” and spirituals before a series of black ministers read from the Bible…
Despite the size and some newspaper coverage of the event, its memory was suppressed by white Charlestonians in favor of their own version of the day. [link]