What were northerners who didn't want to see slavery spread called?

I believe they were called unionists as they were part of the Union. The south was the Confederacy therefore southerners were Confederates.

Ithink that would be false, hope that this .

The social difference that caused sectionalism in the antebellum era would be c.)  north was disorganized. the north had slow population growth, where as the south had mass immigration.hope this really mark