Mamie Elizabeth Till-Mobley was an American educator and activist. She was the mother of Emmett Till, the 14 year-old boy murdered in Mississippi on August 28, 1955, after accusations that he had whistled at a white woman, a grocery store cashier named Carolyn Bryant. For Emmett's funeral, in Chicago, Mamie Till insisted that the casket containing his body be left open, because, in her words, "I wanted the world to see what they did to my boy."
Source