The answer might be d if I’m wrong so sry
I think the main cause was slavery in the economy and society and there were pro slavery and free states so that didn’t work out
Answer:
it accelerated the great migration
Slavery was a key issue in the admission of states into the union. states had to be admitted in pairs, free states and slave states, in order to maintain balance in the union. It was agreed that offsetting the balance would escalate the tension regarding slaverly and tear apart the union.