Harland was in love with Delacorte, who had been sold by a man named Hammersmith to somebody in Georgia. Clint, in the shape of a cougar, mortally wounded Hammersmith, but before he died Harland was able to use the Music Box Key to make Hammersmith to tell him where Delacorte was.
Harland then used the Skin Key to change his appearance to an African-American man,and go to Georgia to save Delacorte. Initially intending to change back to white when Delacorte was saved, he decided he looked better black, and stayed that way for the rest of his life.
At some point Harland was shot by an "ignorant southern bastard." While it didn't initially kill him, the bullet was stuck in his body for the next fifty years, and, in 1912, Harland decided to leave the Earthly plane of existance, together with Ian Locke, by using the Key to the Moon.