The civil warepisode one: the cause 1861 by ken burns3. according to shelby foote, why is an understanding of the civil war so important? 6. according to historian barbara field, if there was a single event that caused the civil war, what was it? 11. why did historian ed bears say that john brown was the single most important factor in bringing on the war? 14. as president, what did lincoln say regarding slavery? 19. what did lincoln do with runaway slaves and why? what did general butler suggest? 21. what was the result of the battle of manassas or bull run in virginia? who turned the battle and became a hero?