The history of the song is that it was written in the early 20th century for school children’s pagent honoring the birth of Abraham Lincoln.
The author and composer quickly forgot it but the 500+ children who sang it did not.
Some of them went to college and taught it to their classmates.
Some of those became teachers and taught it to those in their charge.
Thank you; I learned something tonight.
This was from the era where the great integration debate was between Booker T. Washington (our side) and W. E. B. DuBois (socialist side), with James Weldon Johnson, from what I can tell, straddling the fence and trying to work with both sides. He would make a good subject for a biopic, except that the woke movie industry would destroy the facts for the sake of their CRT lies.