Possible Outcomes of a Divided Nation:

A Southern Slave Confederacy that Exists to this Day
Possible Conquest of the Northern Union by the Southern Slave Confederacy, An American Slavery Nation
Possible Conquest of Nazi Germany, as the divided nation may not have had the strength of arms
Postponement of the Industrial Revolution - that could have been good or bad
Postponement or complete non-existence of Nuclear weapons
In any event, the continued slave state of the African captives- possibly expanded to other nations
The Annihilation of the Jewish race