An image of an Atlanta billboard with a caption that reads "Black Children Are An Endangered Species." TheRadianceFoundation.org hide caption

itoggle caption TheRadianceFoundation.org

First Nation aboriginals perform for International Olympic Committee President Jacques Rogge as he tours the Olympic Village in Vancouver this week. Mark Ralston/AFP/Getty Images hide caption

itoggle caption Mark Ralston/AFP/Getty Images

John Rich is a professor at Drexel University School of Public Health. He was awarded a MacArthur Foundation "genius" fellowship in 2006. Courtesy of Dr. John Rich hide caption

itoggle caption Courtesy of Dr. John Rich

The four original participants in the Woolworth's lunch counter sit-in walk down the street after leaving the lunch counter on Feb. 1, 1960. The Woolworth's sit-ins continued for months and inspired sit-ins across the country, which helped change public opinion and led to the end of segregation. Jack Moebes/Corbis hide caption

itoggle caption Jack Moebes/Corbis