One of the expressed goals of the South was to spread slavery from coast to coast, and from North America and into Cuba and South America. The South was well on its way to accomplishing their goals with the compromises allowed slavery to trickle west, the overthrow of those compromises with the Kansas-Nebraska Act, and their victory with the Dred Scott decision that essentially made Northerners slave catchers and extended the property prerogative North of the Mason Dixon. If you knew your history beyond what your teachers taught you, then you would not make sure a statement.