If you read The Autobiography of Malcolm X you will notice some interesting things about Black attitudes before the Black Power movement. Black men and women used to "conk" their hair. They used a substance called congolene to straighten their natural hair. Congolene burns. Whites often forget that black skin tones differ. There are infinite gradiations in skin color. Back in the day, the lighter your skin was, the higher the status. Lighter skin was associated with white blood.

Malcolm X and others noticed that that status was related to "whiteness", or closeness to a white ideal. By giving status to light skin, blacks were in a way reifying their supposed inferiority. With dress, hair style and attitude they were seen to be mimicing white society. This was seen as accepting inferiority.

As robwicks noted in the w/u above, Black Power came partly as a response to white racism. But also as an affirmation of the essential humanity of african-americans. Black leaders saw their people with a huge inferiority complex. In order to lift them up, they saw the need to first break that complex, to remind their bretheren that they were as good as anyone. The Black Power movement served the purpose of uplifting a people's souls, so they could uplift themselves.

one unexpected side effect was the growth of the afro as a political statement through hair style. If you ask any black woman, they'll happily explain to you why that particular statement was short-lived. Blacks do straighten their hair now, in addition to adopting hair styles more friendly to their curly hair. But now it's a choice of style, not a requirement for status