OKLAHOMA CITY — The Oklahoma Historical Society will commemorate Juneteenth with a free educational program at the Oklahoma History Center on Thursday, June 19. Doors open at 5:30 p.m., and the program will start at 6 p.m.Juneteenth is the celebration of emancipation following the U.S. Civil War. U.S. Army General Gordon Granger proclaimed the end of slavery in Texas at Galveston on Ju...