I'd imagine the southern politicians didn't actually believe that after the decades of wars,treaties,Indian removal,manifest destiny to expand the country that they would be allowed to leave without a fight? If Polk could find a reason to annex Texas then war with the southern states/Confederacy had to have been inevitable if Lincoln is elected right? The general population of the United States would never allow that.
Irregardless of politics involved wouldn't of secession for any reason have lead to immediate conflict?
Irregardless of politics involved wouldn't of secession for any reason have lead to immediate conflict?