Final answer:
The passing of laws banning slavery in the northern states led to a more divided nation by intensifying sectional tensions and fueling disagreement over the expansion of slavery.
Step-by-step explanation:
The passing of laws banning slavery in the northern states contributed to a more divided nation by intensifying the sectional tensions between the North and the South. The disagreement over the expansion of slavery into the newly acquired western territories fueled these tensions. While the North believed in confining slavery to where it already existed, the South wanted to extend it to those territories. The inability to reach a compromise on this issue eventually led to the secession of southern states and the Civil War.