Various "scholars" & "experts" often forget that there are people who have lived the history of which they wax. On both sides of my family, my ancestors have been in North America for over 3 centuries, some were indigenous. I grew up mostly in Oklahoma, where one can still find a wealth of information about the "Buffalo Soldiers" from their relatives, some of whom have told many stories of the Buffalo Soldiers & their Buffalo Gals. As a child, I never tired of hearing the story an elderly lady told me of being a "Buffalo Gal" who came out West on the train after the civil war was over, to hopefully find a husband & a better life. After the war, she had nothing, no relatives, no place to go, but wanted to live where her "African blood" (her words, not mine) was not the measure of a woman or a man-where she could live a free woman.
A visit to museums at Ft. Sill, Oklahoma (adjacent to Lawton) could show the observer informative displays of Buffalo Soldiers, as they were assigned there.

   Oh yes, and I grew up singing the song, too.