Final answer:
The 'Lost Cause Myth' is the revisionist narrative that suggests the South fought honorably and justly during the American Civil War and downplays the role of slavery.
Step-by-step explanation:
The revisionist history myth you are referring to is known as the Lost Cause Myth. This myth created a biased perspective that tried to paint the Southern cause during the American Civil War as honorable and just, often downplaying or justifying the role of slavery and presenting the Confederacy's efforts as a noble struggle for states' rights and individual liberties, rather than the preservation of slavery. Promoters of the Lost Cause narrative typically suggest that the South fought valiantly against overwhelming odds and that their cause was noble, despite it ultimately being on the wrong side of history.