Christine and Millie McKay, American conjoined twins, c 1870s.
© Science Museum / Science & Society Picture Library
Carte de visite of 'The Two-Headed Nightingale'. Millie and Christine McKay (1851-1912) were connected at the base of the spine. Born into slavery in America's South, they were sold to be displayed as a 'freak show' and toured the Northern USA and Europe singing duets and accompanying themselves on the keyboard before returning to their family. After being exhibited for many years, they were finally set free and earned enough money through their performances to buy the plantation where they were born, and to endow schools and colleges for black children.