There were radical elements in the North who wished to do that, but they were not even a controlling element in the Republican Party. The South had more than a sufficient number of Northern allies to protect their domestic life.
But the Republican tide was a mortal threat to the expansion of slavery in the territories.
If the issue was merely sustaining non-interference in the slave states, the logical course would be to continue in alliance with the moderate North. Secession only made sense if the motivation was the militant radical spread of slavery.
Please explain how the secession of South Carolina was an attempt at the "militant radical spread of slavery".
Looks to me like SC was trying to avoid federal interference and was protesting violations of the constitution. There is nothing in the secession of SC that had anything to do with spreading slavery.
Sorry, but one of the MAJOR issue was the tariff. The South shipped a lot of cotton overseas and wanted to bring stuff back in cheaply. The North wanted to hold the South as a captive market and raw material source through high tariffs. Essentially the North wanted to practice mercantilism against the South.
After the South seceded, the Northern industrialists and merchants had visions of grass growing in the streets of New York and Boston, because of low (10%) tariffs in Charleston and New Orleans. The Federal Government had visions of bankruptcy (approx. 75% of the Fed’s revenues came from the South). The fact that the South controlled the mouth the Mississippi made this all the worse.