Green’s Dictionary of Slang

(US) any primitive rural area; thus used pej. of those who live there; also attrib.

1941		C.S. Johnson Growing Up in the Black Belt 39: Schooled to an inadequate diet and to eking a scant living out of a poor soil, they live on ‘Tobacco Road,’ [...] proud toward upper-class whites, and inhospitable to the Negro.
1981		J. Ellroy Brown’s Requiem 148: [of Baja, CA] [D]wellings that ranged from ‘Tobacco Road’ sharecropper shacks to proudly tended stucco four-flats.
1989		Kirk & Madsen After The Ball 233: Two leathery dykes from tobacco road.
1997		(con. 1970s) G. Pelecanos King Suckerman (1998) 31: Opening the pack from the bottom, that was just like a tobacco road Bama.