On a sparsely traveled road in downtown Lexington, African Cemetery No. 2 sits encircled by a worn iron fence. The sounds of cars flashing by nearby busier streets, the incessant barking of a neighboring dog and the harsh droning of a drill from the adjacent auto parts shop carry through the isolated eight-acre plot. Opened in 1869, the site now contains over 5,000 graves, of which fewer than 600 are recognized with markers. The plot inters hundreds of enslaved African Americans, as well as members of the U.S. Colored Troops...