Green’s Dictionary of Slang

(US) an area of a town in which the black population live.

[1914		Ade ‘The New Fable of the Marathon in the Mud’ in Ade’s Fables 282: It was known that the agitated Yahoos from up in the Catfish Country were likely to fumble and spill their saved-up Currency].
1925		Du Bose Heyward Porgy (1945) 41: There was great rejoicing in Catfish Row. [Ibid.] 67: ‘But ef dat yalluh nigger come tuh Catfish Row agin — leabe him fuh me — dat’s all!’.
1936		George Gershwin [title] Catfish Row.
1948		D. Burley N.Y. Amsterdam News 7 Feb. 12: Georgia’s Tobacco Roads and Virginia’s Catfish Rows.
1960		(con. 1940s) I. Freeman Out of the Burning (1961) 32: Larry walked out of the apartment in disgust. ‘Jesus, Catfish Row!’.
1961		C. Himes Pinktoes (1989) 21: Most Negroes live together [...] in their own communities, such being known as [...] ‘Catfish Row,’ and ‘Possum Run,’ and ‘Chitterling Switch.’.
1965		C. Brown Manchild in the Promised Land (1969) 329: The kind of temptation one might see on Catfish Row at the end of the cotton season.
2002		in N.Y. Times 5 Mar. 🌐 As the lights go up in a dingy square of Catfish Row [...] you see a teeming street: rowdy men playing craps and picking fights, women hassling their husbands, wet clothes hanging, peddlers selling honey, crabs and ‘happy dust.’.