So, I'm guessing maybe you had Covid, or some other valid excuse, and missed the class where we discussed this in great detail, right?
The shorter version is: of course, the Union under Democrat President Buchanan did "let the states withdraw".
President Buchanan did nothing while Deep South Fire Eaters:
Little known fact: in the Civil War's first year, more battles were fought in Union states & territories than in the Confederacy, including in Union New Mexico, Oklahoma, Missouri, Kentucky, West Virginia and Maryland.
Actually I did not know the Confederacy declared war first.
So the Confederate politicians overplayed their hand in the beginning.
Which was both arrogant and stupid with the result of half a million white men dead.
As always the common man pays for the mistakes of those people in power.
Actually I was diagnosed with COVID but generic flu medicine, aspirin, menthol cough drops and plenty of rest saw me through. No ivermectin was available thanks to Dr fakey and the big pharma. I did get 5 day antibiotic prescription five days after onset AFTER the fever had broken......