Glory too realistic?

What surprised me right from the start of the movie was the treatment of the black soldiers. I couldn't really imagine racism to that extent because today we have very few racist people and usually not in the United States. For example Kernel Robert Shaw had known Thomas for so long and yet when their friendship came to the test he treated Thomas like another dirty dog that had to learn manners. Also what surprised me was that white Kernels could be so cruel. In the scene where they burned the village, the kernel with Shaw shot his own soldier without even giving orders or directions. What made me think was when at the end They buried Trip and Shaw together. That was the last question, but i never really understood it so my feelings on it were that there was no significance. I thought it might have been a coincidence even though Robert and Trip had talked about their futures together. Also what made me think was how Trip got along with Robert even after staring into the eyes of cruelty while getting whipped. I learned that the African Americans endured many hardships in the army; more so then today at least. This movie showed not telled (I did that on purpose) me how the lives of colored soldiers were so it helped me grasp the concept more. I think this movie was realistic with more of a Hollywood twist to it then Mr. Harp described because in the battle scenes none of the stars died only the random colored actors. Other than that the storyline looked pretty accurate to me, but that could just be because I have never heard of the 54th Massachusetts regiment in my life.