I understand your sentiments, but breaking up over the issue of slavery would not have gone well. The south turned a legit issue... States rights .. into something ugly... the right to have slaves. We all have regrets in our life. the south most certainly regrets this stain on its history.
You are not going to like this link regarding Lincoln's efforts to protect slavery.
Respectfully disagree. Slavery was bad but was it worth over 1 million dead and the destruction of the South? A big part of the tensions were the north putting export tariffs on agricultural products produced in the South and import tariffs on good imported from Europe. These tariffs occurred after the Compromise of 1850 that gave non-slave states the majority in the Senate.