(AP file photo) In this 1960 photo, Martin Luther King Jr. speaks in Atlanta. The civil rights leader had carried the banner for the causes of social justice — organizing protests, leading marches and making powerful speeches exposing the scourges of segregation, poverty and racism. Following the publication of "An Appeal for Human Rights" on March 9, 1960, students at Atlanta's historically black colleges waged a nonviolent campaign of boycotts and sit-ins protesting segregation at restaurants, theaters, parks and government buildings.