The social historian Brian Carso notes that as the 19th century progressed , the story of Arnold 's betrayal was portrayed with near-mythic proportions as a part of the national creation story . It was invoked again as sectional conflicts increased in the years before the American Civil War .
Social historian Brian Carso notes that as the 19th century progressed , the story of Arnold 's betrayal took on near-mythic proportions as a part of the national creation story , and was again invoked as sectional conflicts leading up the American Civil War increased .