Answer:
The abolition of slavery
Step-by-step explanation:
This would be the most accurate answer because the K-N act was created to allow for popular sovereignty in addition to two new US territories. This would led to conflict between people for vs. against slavery. The dred scott case was not influential in the K-N act considering it was a court case fought over slaves being property in the south. The transcontinental railroad and expansion of banking were not involved with the K-N act.