I believe one of the great sins of American Christianity was that it failed to fully embrace the equality and fair treatment of all people, regardless of their racial origin. Ours is a belief system after all that requires us to love our neighbor, and believes that God does not show favoritism or preference with regard to persons.
That being said, there is no denying civil rights movement was a profoundly Christian effort, particularly as embodied in the person of Dr. Martin Luther King. Jr., and would not have had the impact it had absent the moral force and language of his belief. It is good that we honor him.