Before the Civil War began, which issue played the GREATEST role in increasing tension and conflict between northern and southern states?

Question

Responses
A northern opposition to the Tariff of 1832.
B westward expansion and the issue of how to seize land owned by the Native Americans.
C westward expansion and the issue of whether slavery would be allowed in the new territories.
D the Indian Removal Act, the "Trail of Tears," and the creation of Indian reservations in Oklahoma.

Answer 1

The issue that played the GREATEST role in increasing tension and conflict between northern and southern states before the Civil War was:

C westward expansion and the issue of whether slavery would be allowed in the new territories.

This issue directly contributed to significant conflicts such as the Missouri Compromise, the Compromise of 1850, and the Kansas-Nebraska Act, all of which heightened tensions between anti-slavery and pro-slavery factions.