Well, Mr Byron ed, your author did well explaining why the rape statistics are lower than they should be - very hard to report it and then it's to be handled by an all male judiciary. If you're non-white in that day, nominal recourse and you're automatically considered to have complied with it by merely being of color. Yes, indeed, a soldier would get away with it that way a lot easier than with a white woman. There's where status comes in. Poor white women had just about the same options as non-white.
Once in a while the soldiers did not get away with it so easily. Forrest's men once came upon a half dozen Union soldiers engaged in this at a farm and killed every one of them. Period. It was duly reported to Union authorities and duly filed with no comments or further action. Custer did the same thing when he encountered two women running down the road toward him, pointing out their attackers, who were two of his own command. He nailed one with a hatchet, the other appears to have survived a pretty good thumping. No official report but credible eye witness account. It needs to be noted the victims in both these cases were white. If they had not been, likely nothing would have happened to the soldiers involved.
Invading armies everywhere have a psychological warfare more or less built into the species, one might say. We're taking all you have - and we mean ALL - and you can do nothing about it. We won - this proves it. Sherman was again right - you can't refine war.