Aggie_Journalist said:
Another fun question is: Why did the south agree to prohibit slavery in the northwest territory back in 1787?
Best I can tell, at that point the slave states didn't want additional slave states because they feared the competition would drive down plantation profits. Over the next few decades, as the country expanded and southerners wanted to move westward, they wanted to take their slaves with them and their position changed. Over further decades, southerners became paranoid about northern abolitionists ending slavery altogether, and then it became more about which region would force its will on the other.
I believe it's a couple of things:
1. It's my understanding that many thought slavery was a dying institution in 1786 for the most part. I've never seen any actual evidence to support that but people smarter than me seem to believe that.
2. They southern slave states were hoping to limit agricultural competition at the time.
Once cotton became King and the economic elites believe that they needed slavery now more than ever, they felt that it must be protected. To do that, they had to at least hold 50% of the Senate because the House was lost to them due to immigration, even with their unfair 3/5ths advantage. So newer slave states had to be added out west.
If you say you hate the state of politics in this nation and you don't get involved in it, you obviously don't hate the state of politics in this nation.