Why was white america so fascinated by harlem in the 1920s

"When the Negro Was in Vogue" by Langston Hughes, Here's a quote from his book that might help you out.

White people began to come to Harlem in droves. For several years they packed the expensive Cotton Club on Lenox Avenue. But I was never there, because the Cotton Club was a Jim Crow club for gangsters and monied whites. They were not cordial to Negro patronage, unless you were a celebrity like Bojangles. So Harlem Negroes did not like the Cotton Club and never appreciated its Jim Crow policy in the very heart of their dark community. Nor did ordinary Negroes like the growing influx of whites toward Harlem after sun- down, flooding the little cabarets and bars where formerly only colored people laughed and sang, and where now the strangers were given the best ringside tables to sit and stare at the Negro customers—like amusing animals in a zoo.

Hope this helps, have a BLESSED and wonderful day! As well as as a safe one! :-)

-Cutiepatutie ☺❀❤