He also mentions that up to 80,000 civilians may have been killed. Almost all of them Southerners.
After he mentions Andersonville prison camp, he does mention the truth that more Confedrates died in Union POW camps than Unioners died in Confederate POW camps.
I agree that it was very tragic to have 620,000 American soldiers and up to 80,000 Southern civilians killed.
But I would say that most Yankee sympathizers still vigorously defend the Northern aggression and treachery and brutality of the war.
Many of them even defend the war crimes against civilians of the South.