Fifty years ago, hundreds of young white and black Americans united to desegregate buses across the South. These Freedom Riders, as they came to be known, drew vivid attention to the inhumanity of segregation, and their collective action marked a turning point in galvanizing white support for the civil-rights movement. Since the summer of 1961, many Americans have continued to fight widespread inequality and racism. Yet despite remarkable progress -- including the election of an African American president -- many forms of racial injustice remain deeply entrenched in American society.