“In Cuba, there is no fear of a racial war. Men are more than whites, mulattos or Negroes. Cubans are more than whites, mulattos or Negroes. On the field of battle, dying for Cuba, the souls of whites and Negroes have risen together into the air.”

The Conquest of a Continent (1933)

1860s, Allow the humblest man an equal chance (1860)
Context: So that saying, "in the struggle between the negro and the crocodile," &c., is made up from the idea that down where the crocodile inhabits a white man can't labor; it must be nothing else but crocodile or negro; if the negro does not the crocodile must possess the earth; [Laughter; ] in that case he declares for the negro. The meaning of the whole is just this: As a white man is to a negro so is a negro to a crocodile; and as the negro may rightfully treat the crocodile, so may the white man rightfully treat the negro. This very dear phrase coined by its author, and so dear that he deliberately repeats it in many speeches, has a tendency to still further brutalize the negro, and to bring public opinion to the point of utter indifference whether men so brutalized are enslaved or not.

Malcolm X Speaks (1965)

1960s, The Role of the Behavioral Scientist in the Civil Rights Movement (1967)

1960s, Address to Local 815, Teamsters and the Allied Trades Council (1967)

W.E.B. DuBois, Birth Control Review, June 1932. Quoted by Sanger in her proposal for the "Negro Project."
Misattributed

Source: To Kill a Mockingbird

1960s, The Role of the Behavioral Scientist in the Civil Rights Movement (1967)