Fifty years ago this week, Medgar Evers, the NAACP regional secretary in Mississippi, was murdered by a member of the White Citizens’ Council. Evers’ death received national attention, serving only to strengthen the movement for civil rights. Two years later, President Lyndon Johnson delivered a historic commencement address at Howard University, laying out progress made and challenges unmet. Johnson praised the “indomitable determination” of African Americans demanding their freedom. He hailed the Supreme Court for outlawing segregation, as well as Congress for passing the first civil rights legislation in 100 years. The barriers to freedom are tumbling down, but “freedom …