Why did the Southern Democrats and the Northern Democrats have two separate candidates?

The Southern Democrats and Northern Democrats had two separate candidates in the 1860 presidential election primarily due to deep divisions over the issue of slavery. Southern Democrats wanted to protect and expand slavery, while Northern Democrats were more focused on popular sovereignty and preventing the spread of slavery into new territories. These differences were exacerbated by regional interests and political ideologies, leading to a split in the Democratic Party. As a result, the two factions nominated separate candidates: John C. Breckinridge for the South and Stephen A. Douglas for the North.