“...or federal authorities decided to ignore the war crimes because . . . because why? “
Because evidence after a battle is very hard to collect, and because no one really KNOWS what happened. Even now.
One of my favorite generals wrote:
“The massacre at Fort Pillow occurred April 12, 1864, and has been the subject of congressional inquiry. No doubt Forrest’s men acted like a set of barbarians, shooting down the helpless negro garrison after the fort was in their possession; but I am told that Forrest personally disclaims any active participation in the assault, and that he stopped the firing as soon as he could. I also take it for granted that Forrest did not lead the assault in person, and consequently that he was to the rear, out of sight if not of hearing at the time, and I was told by hundreds of our men, who were at various times prisoners in Forrest’s possession, that he was usually very kind to them. He had a desperate set of fellows under him, and at that very time there is no doubt the feeling of the Southern people was fearfully savage on this very point of our making soldiers out of their late slaves, and Forrest may have shared the feeling.” - Major General William Tecumseh Sherman
Wiki has a good article here:
https://en.wikipedia.org/wiki/Battle_of_Fort_Pillow
I don’t think there is any doubt that in the heat of battle, many southerners behaved horrifically toward blacks who fought them. I haven’t seen any evidence their leaders pushed them to do so, or that it continued after tempers cooled.
I don't think there is any doubt that in the heat of battle, many soldiers behave horrifically against enemy soldiers.
https://www.youtube.com/watch?v=I7dmcHoODZI
I don't know if the scene depicted above was based on a specific incident, but in the 1990’s a WWII veteran volunteered to me that prior to D-Day his commander addressed the company and said, “we don't need a lot of prisoners.”
The veteran added, “that was all he said and we knew what he meant.”
If someone told me that in four years of war not one southern soldier ever committed an atrocity, I'd be surprised.
On the whole, I believe southern commanders and soldiers conducted themselves honorably; especially when viewed in the context of the north's total war..
LOL! Bullchit. They didn't press charges and there was no evidence because there was no such "massacre". Had you actually read the congressional testimony you would know that. You would know that: 1) Forrest was well in the rear. His horse had stumbled and rolled over him a few days earlier breaking a couple of his ribs. He was not healthy enough to lead from the scene as he usually did. 2) far from massacring federal prisoners, he handed them over to the Confederate medical corps and kept a receipt for them which he was able to produce for Congress and entered into evidence. 3) there was no "massacre". There was a running battle with federals fleeing and some taking shots and with Confederates pursuing and shooting. Undoubtedly some who were trying to surrender were shot as always happens in such scenarios when some from the losing side are running away and some are still shooting.