An overpowering sense of moral righteousness. I am not saying that I agree with their righteousness, but it seems to be a motivator.
I have possessed a pallet full of bound Yankee newspapers encompassing the years 1860-1865. They were New York and Philly papers. Still have a few bound books. The propaganda is blatant, moralistic and righteously indignant.
As opposed to the southern newspapers of the period, in which the propaganda was timid and entirely accepting of the righteousness of the other side’s cause.