Explanation: During the US Civil War, the pro-slavery South attempted to secede from the (tepidly) anti-slavery North. In the process of the Civil War, General Robert E. Lee obtained, both contemporarily and in the retellings of the "Lost Cause", a disproportionate reputation for military genius.

The truth is that the first few generals of the Union Lee went up against were varying shades of incompetent, and the moment a competent Union leader (Meade) was installed, Lee's 'stunning' victories dried up. When a man of genuine strategic vision was appointed (Grant), Lee's fortunes changed from "suffering unsustainable losses" to "suffering unsustainable losses as the Union tightens a noose around the Confederate heartland."

Lee was a competent tactician, but had very little strategic ability, and no understanding of the type of industrialized total war that the US Civil War introduced.