 However, the earliest recorded reference to this event did not appear until many years after.Regardless, mention of the observance is inscribed on southeast panel of the Confederate Monument in Jackson, erected in 1891.On May 1, 1865, in Charleston, South Carolina, recently freed African-Americans held a parade of 10,000 people to honor 257 dead Union soldiers, whose remains they had reburied from a mass grave in a Confederate prison camp.