Respuesta :
It was primarily the issue of slavery that led to the split in the Democratic-Republican Party in the late 1850s, since this was the dominating issue of the age, as the US continued to expand to the west.
I believe the answer is: Issue
At that time, the democratic party predominantly support slavery and the Republicans wanted to abolish it. The disagreement between these parties create a high tension between southern and northern states which led to the declaration of the civil war.
