Historian Burton Perreti's 2007 well researched history of New York City nightlife includes a detailed 10-page background of the 1926 Cabaret Law which refutes any claim that the law was directed at Harlem, jazz, and interracial nightclubs. For Mayor Walker, the Cabaret Law was intended primarily to provide a closing time of 3:00 AM and was intended to bring the new nightlife under effective government oversight.
Professor Perretti, relying upon original sources, provides a fascinating account of nightclubs, speakeasies, and cabarets in New York City. In Chapter 3, Perretti describes earlier laws froom 1913 on regulating dance halls and establishing closing hours of 1:00 AM and the infatuation of the City with licensing of bathhouses, bootblack chairs, billiard parlors etc. Perretti at one place cites to Chevigny’s book, but omitted any of Chevigny’s claims of racism.
Unlike Chevigny who provides no citation to support his conjecture, Perretti cites to many articles available in the New York Times archives: example, Night Clubs’ Curfew Enters Another Cycle – Why Mayor Walker Determined They Must Close At 3 A.M. — Gaynor And Mitchel Also Had To Restrict Revelry During The Dark Hours. New York Times January 2, 1927.