Millie and Christine McCoy (1851)

Millie and Christine McCoy were American conjoined twins born to slaves and sold to showman J.P. Smith as infants. A rival showman kidnapped the girls, but Smith reclaimed them. He taught them to speak five languages, play music, and sing, and the twins enjoyed a successful career under the stage names “The Two-Headed Nightingale” and “The Eighth Wonder of the World.” In 1912, the girls died of tuberculosis just 17 hours apart. What was the title of the book sold at their public appearances? Discuss

Source: The Free Dictionary