Green’s Dictionary of Slang

(US black) one who has kinky hair; thus a black person.

1860		in Alabama Hist. Quarterly XLIV (1982) 95: We found [...] plenty of kinky heads out picking cotton [HDAS].
1916		J. London ‘The Princess’ Complete Short Stories (1993) III 2463: I ran in cargoes of kinky-heads from Malaita, in the Solomons until I had twelve hundred of the blackbirds putting in cane.
1929		C. McKay Banjo 241: You’re the poorest kinky-head I ever did see.
1944		Mencken ‘Designations for Colored Folk’ in AS XIX:3 173: When, in 1936, Cab Calloway, the Negro musician, used kinky-head in a broadcast, he was violently belabored.
1959		S. Kennedy Jim Crow Guide to the USA 165: ‘Is there a law for kinkyheads?’ a Florida Negro Freedman bitterly asked the white man who had just defrauded him of his farm.
1965		M. Tolson Harlem Gallery I 78: If you make me a poem, Hideho, I’ll make you my one and only daddy-o till the Statue of Liberty dates a kinkyhead.
1970		(con. 1930s) E.R. Ellis Nation in Torment 395: As regards racism, [Huey Long] did tell Negro stories in dialect and called some of his foes ‘kinkyheads,’ but he also made a public apology for using the word.