On April 5, 1968, the day after Martin Luther King Jr.'s assassination, Riceville, Iowa schoolteacher Jane Elliott ran an incredible social experiment in her third grade classroom. Her "Blue Eyes/Brown Eyes" exercise identified the kids "as inferior or superior based solely upon the color of their eyes and exposes them to the experience of being a minority." The exercise had a tremendous, and lasting, impact on those children and countless others, and sparked Elliott's lifelong role as a an anti-racism activist and educator.
Above is a 1985 episode of Frontline about Elliott. Below is her appearance last week on The Tonight Show: