MLK was instrumental in the progress of the Civil Rights movement.
You know who Rosa Parks is right? Who was the voice of the Birmingham Bus Boycott? MLK.
Who acheived a feat that few black men of the time could claim when he actually made some white people listen up? MLK.
Who, through his religious background & constant quoting of the Bible, made it hard for the racist white groups to demonize him & thus, other black people? MLK.
To go into MLK's history & profound effect on the Civils Rights movement would be a lengthy & somewhat arduous task & frankly, I can't be bothered. Read up yourself.
As for Malcolm X, I'll just say he is a shining example of the advancement of a human being. He went from nobody, to drug dealer, to inspirational - yet racist - spokesman for the N.O.I & then came to see that all human beings are equal.
Like MLK, there is so much more to him but I don't have the time nor inclination to accomodate you. Once again, read up & be illuminated.