Minstrel shows were preformed by whites wearing black make-up.

Incorrect. Minstrel shows were performed mostly by blacks, who wore make up to exaggerate their features, as was common in all old theaters with their primitive and dim lighting. These shows featured song, dance, and often rather earthy humor.

Just as whites adopted and/or adapted blues and jazz, some whites, too, got into doing minstrelsy (and Jews, hello, Al Jolson).

Just as Thomas Sowell relates that the historically black colleges and universities suddenly went on a black-only hiring binge, so too, starting in the 1930s, did a bunch of people (almost all Leftists) start to decide that black people making fun of themselves was Politically Incorrect. This is what killed Amos & Andy (an undeserved death which Smokey Robinson once lamented).

For more on the unwritten law against black comedy, let Jimmie Walker tell you.