Interesting thread !
It is amazing how long black face continued to thrive. Of course there was Amos and Andy which was very popular almost everywhere as both a radio and a TV show (and I remember the TV show from my childhood).
Many have never heard of Emmett Miller but he was a popular vaudeville singer and performer of black face and minstrel shows who actually made it to the TV era. His original shtick, aside from the black face routines, was his voice which he used to yodel songs. He's widely thought to have influenced Jimmie Rodgers to incorporate yodeling as they toured together before Jimmie was well known. Emmett also wrote Lovesick Blues which was made famous by Hank Williams (and features Miller's yodeling style). I think there's maybe some YouTubes of Emmett.
Just thought I'd throw that in.
Oh yes, Amos and Andy are outgrowths of the Minstrel genre. Prior to the Civil War all Blackface was performed by white males. Afterwards a number of African American actors and performers formed their own troupes and in Blackface did the same routines. Some film historians even relate shows like Sandford and Son and The Jeffersons to further iterations of the genre.