Millie and Christine McKoy were conjoined twins who toured the world as "The Carolina Twins" and the "Two-Headed Nightingale" during the 19th century. The children of slaves, Millie and Christine spent time working for P.T. Barnhum as human oddities but were able to transcend that label and achieve international fame. As the only African-American conjoined twins of their time, they received attention from royalty, doctors, and audiences alike, while being poked, prodded and gawked at for their entire lives. Their tragic end, however, may be the most heart-wrenching part of their story.