One of the most fascinating areas of politics in the modern world was the rapid radicalization of Black America in the Sixties. From the Civil Rights movement through the work of Sokeley Carmichael and the emergence of Eldridge Cleaver and on to the launch of the Black Panthers, the process took barely half-a-decade: the two key images of the era - Martin Luther King's 'I have a dream' speech at the Lincoln Memorial, and Tommie Smith and John Carlos giving the Black Power salute at the Mexico Olympics - were separated by just five years.
Here's a random selection of texts from the movement:

Martin Luther King Jr Why We Can't Wait

Lerone Bennet Jr What Manner of Man

Soul Brother #44 Why We March

E Franklin Frazier Black Bourgeoisie

Alan F Westin (ed.) Freedom Now!

Eldridge Cleaver Soul On Ice

Eldridge Cleaver Post-Prison Writings and Speeches

Lee Lockwood Conversation with Elridge Cleaver

Stokeley Carmichael & Charles V Hamilton Black Power

Huey P Newton Revolutionary Suicide