WI and PC: Slave Rebellion leads to Northern Secession

Alcsentre Calanice

Gone Fishin'
What if a slave rebellion (for example in the context of a more successful raid on Harpers Ferry) breaks out under a pro-slavery president (like Buchanan)?

The president tries to summon the army and national guards against the slaves, leading to numerous cases of insubordinance in the army and finally to the mutiny of certain regimes. Would northern states follow such a movement? Is a northern secession against a southern-dominated Union possible in such a scenario?
 
First, this belongs in pre-1900. Second, while northern secession is very unlikely in any event, if it happens the cause will not be federal suppression of a slave revolt. Few northerners really approved of slave revolts, even if they admired John Brown's courage. Lincoln and Seward both condemned Brown, Seward saying that Harpers Ferry was "an act of sedition and treason" and that the hangings of those involved were "necessary and just" though "pitiable." https://books.google.com/books?id=ChI3Yh2uqv0C&pg=PA361 Northern secession for other reasons (like Lincoln's feared "second Dred Scott decision" legalizing slavery in the states or a war seen as one for slavery expansion into Latin America) is also unlikely but a bit more plausible.
 
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