Question

tensions mount
throughout the first half of the 1800s tensions mounted between northern and southern states over the issue of slavery. to prevent conflict, congress attempted a strategy of appeasement. appeasement means to try to keep both sides happy in a conflict.
with compromises like the missouri compromise of 1820 and the compromise of 1850, conflict was prevented, but tensions continued to rise until the start of the civil war in 1861.
what issue caused tensions to rise between northern and southern states during the 1800s?
voting rights
taxes
slavery

Explanation:

The text explicitly states that tensions mounted between northern and southern states over the issue of slavery in the first half of the 1800s, with compromises (like the Missouri Compromise) attempting to address this conflict.

Answer:

slavery