A fals analogy huh? Well, try this one. We know that the Garrison at Ft. Pillow was some 557 men of which some 262 (13th Tennessee Infantry) were White, and some 295 USCT, of which number around 20 were White officers. We also know that both Union and Confederate accounts agree that the number of bodies buried was 228-231. That would mean at least 326 survivors from the Union garrison. Accounts of 300+ USCT "massacred" are simply impossible to reconcile wit these numbers. Now, if the guards at Camp Douglas executed around 200 Black Confederates, that would have been more than the number of USCT killed at Ft. Pillow, not to mention that many if not most of the deaths of USCT at Ft. Pillow resulted from direct combat i.e., they were NOT "executed". Yet you call Ft. Pillow a "massacre" for which you blame Forrest, while absolving the command at Camp Douglas of any responsibility for a policy carried out not once, but repeatedly over several years. Who was it who systematically killed Black POWs, again?
By the way, from the compiled Union and Confederate documentation in the OR (no, I am NOT going to put the citation out here again; it's been posted, and you can just go back and find it for yourself!) Forrest had a total force of no more than 1500-1600. Even at that, had Forrest ordered No Quarter, the Confederates could easily have killed the entire garrison. This did NOT happen, because there was no such order given. The entire action took place in fifteen minutes or less, from the initial charge to the end of the shooting by the river.
Forrest's forces killed unarmed, surrendering African-American federal soldiers. That' not in dispute. At least one Southern soldier contemporaneously stated that Forrest gave that order. The issue is, whether Forrest was responsible. He was in command. Did his troops automatically kill black Union troops? What was Jefferson Davis' policy regarding black Union forces? It was to send them to state authorities, where it was a capitol offense for any black person to bear arms. It was only when Lincoln and Grant threatened to execute one for one, any African-American soldier, a rebel POW, that Davis punked.
You seem to forget that the underlying cause for this war was the mindset that human bondage was OK, because of the base white supremacy notion that blacks were subhuman. Not only did these scumbags believe that slavery was OK, but they had the right to expand it wherever they chose.
Lucky for the elite of the day, there were plenty of idiots who would fight their battles, against their individual interests. Sorta like how people like the Koch Brothers lead the Tea Baggers around by their nose today.
The fact remains. No one tried to stop secession. It was the South who attacked US property to start the war, and they did so because they knew that secession wouldn't hold without a war. Your defense of the pig Forrest reminds me of how the right wingers supported Lt. Calley after his conviction in the My Lai massacre.