But Kansas was resolved through the ballot. Arguing it presaged the war holds about as much water as saying John Brown revealed the North’s secret plans.
You bring up the Missouri Compromise, but for some strange reason fail to mention that it worked and along with Dred Scott it practically settled the issue of the westward expansion or nonexpansion of slavery. Despite countless history books, that was not at issue. Slavery had nowhere to go, at least not in that direction.
As for the Fugitive Slave Act, it did override state prerogatives, but it was not destructive of state rights or the federal system as you imply. The federal government had various powers wand no one of them makes the states slaves to it. Especially not federal powers that people generally assent to, and despite abolitionists the fugitive slave law was not unpopular. Republicans in fact proposed strengthening it through constitutional ammendment.
No, the Compromise of 1850. As for Dred Scot settling rhe issueof slavery expansion, on the contrary, it allowed a farmer to bring slaves into Iowa and work factory farms. . Kansas? That lead to a split between Douglas and the new Buchanan administration from the start. Ironically, it almost led the Republicans to throw their votes to Douglas as senator from Illinois. It did make Douglas unelectable, because the Firebreathers wouln’t forgive him. That opened the way for the Republicans in 1860.