Green’s Dictionary of Slang

(US black) a black person.

1926		Van Vechten Nigger Heaven 208: Look at duh spagingy-spagade talkin’ wid duh fagingy-fagade.
1946		Mezzrow & Wolfe Really the Blues 217: This cat should of been born J. B., he collars all jive and comes on like a spaginzy.
1958		Hughes & Bontemps Book of Negro Folklore 487: spaginzy, spaginzy-spagade : A Negro.
1983		I.L. Allen Lang. of Ethnic Conflict 47: Color Allusions, Other than ‘Black’ and ‘Negro’: […] spaginzy [1950s. Perhaps related to spade, altered to spag. Note that formed like ofaginzy, a black term for whites].
1992		D. Pinckney High Cotton (1993) 140: I would come to no good among the no accounts, burrheads, shines, smokes, charcoals, dinges, coons, monkeys, jungle bunnies, jigaboos, spagingy-spagades, moleskins, California rollers, Murphy dogs, and diamond switchers.