Good thought provoking reply. Thanks.
The southern economy wasn't completely based on slavery, but slavery contributed much to it. Many farms had no slaves.
Your response to #3 is informative. I'll need to read further on that point.
And YES I should have included a fifth point.
5. The northerners wanted to remove FOREVER this point of contention, so that slavery could never again be an issue, and further divide the nation. Slavery had caused sour relations within the union since the slave rebellion in 1832. (Forgot the rebellion name, can you recall it?)
Are you talking about Nat Turner? There were others, but that's the one that mostly gets talked about.
But slavery was an issue even before that. The whole hubbub over the Missouri Compromise was in 1820, which Thomas Jefferson said was "as though a fire bell had rung in the night."