(WJAR) — Friday is Juneteenth, a national holiday marking the day when Union troops arrived in Galveston, Texas to announce that slaves were officially free. The announcement happened in 1865, two years after the Emancipation Proclamation. "We have the richest black history in America, and no one knows,” said Ray Rickman, Executive Director of Stages of Freedom. File image of a Juneteenth parade. (WJAR) "The oldest existing black church is on Convent Street, four blocks from here, created in 1819.