I think social engineering of the day to control people to conform (uh hum, force) societies agenda. Societal myths and lies are dangerous. It has made our heros into the villains, and the Devils are now the saints.
I think Lincoln's position changed during the war from all his life prior to the war.
Other great leaders of the world have suffered the defamation from the power elites, and media.
The truth becomes distorted as it is passed down the line.
History is told by the victor. The loser is not allowed to speak, or is forced to compromise.
The Art of War is deception.