Why couldn't the United States create or democracy in the 19th century without civil war ?

Democracy is a system of government by the whole population or all the eligible members of a state, typically through elected representatives. The Northern wanted to abolish slavery and basically have a clean slate, where everyone was equal and to make a system to keep the people organized and safe, no matter what color anyone was. However, the southerners wanted to keep slavery and would fight tooth and nail for it (even if the war could have been avoided). The united states needed to be together (whole) if they wanted this new system to work. This is why, I think, the united states couldn't create democracy in the 19th century without civil war. Hope my answer helps! If it did, please give meh brainliest, also have a nice day/night :)