[Frumious Bandersnatch]

As for tariffs, the South denied them, felt their economy threatened by them.

Not so true as you believe.  The north also complained about the tariffs - which were designed as much to protect southern agriculture as northern manufacturing.  In point of fact, it was the south which designed the tariffs to begin with.

[Democratic_Machiavelli]

But the Northern states didn't announce that their ability to govern superceded the federal government.

I didn't know the South designed the tariffs. Source?