Charley, that's an interesting song. I've never seen it in print before nor have I heard of it.

I do agree that the song writer was ahead of his time in that he integregated heaven way back in 1899.

Even today, it's very rare to see angels depicted as being
non-White. I think this may have something to do with the color white being considered the sign of purity. But even if the motive isn't racist, imo, there could be and likely is a cumulative negative effect to seeing angels [and God, and Biblical figures including Jesus, and the disciples] as only White.

Green Pastures
is a 1936 movie that I remember seeing as as a young adult as a television special. In the movie "God, heaven, and several Old Testament stories, including the Creation and Noah's Ark, are described supposedly using the perspective of rural, black Americans." I seem to recall that the movie had quite a bit of stereotypical speech and typecasting. But the fact that God and other people from the Bible were depicted as Black had a profoundly positive effect on me.