Green’s Dictionary of Slang

(US) a derog. term for the black section of a town or city; also attrib.

1910		Spokane Press (WA) 28 Feb. 6/2: ‘The Wyoming Whoop‘ [is] the name of a newspaper [...] in Dinktown.
1914		Sun (NY) 10 May 8/1: A dink-town Dink was masquerading as a salesman [...] Then he writes the little fiddling concern to kindly go blitzen with their dinktown policy.
1927		‘J.M. Hall’ Anecdota Americana I 6: The Dinktown band was doing its best when someone called the piccolo player a Cock-sucker.