Final answer:
Northerners saw the South's advocacy for low tariffs, the political influence of slave power, and the deficiencies of a slave-based economy prohibiting social and economic mobility for non-slaveholders as the primary problems facing the South before the Civil War.
Step-by-step explanation:
What Did Northerners See as the Biggest Problems Facing the South?
Northerners identified several critical issues within the South preceding the Civil War. They perceived the southern stance on low tariffs, which hindered economic policies beneficial to the North, as problematic. Additionally, the slave power conspiracy was seen as a dominating force in national politics, driving a wedge between the North and South. This conspiracy comprised the South's political influence used to protect and extend the institution of slavery nationally. Furthermore, they were concerned about the absence of social and economic mobility for poor whites in the South due to the slave-based economy. They believed that the qualities inherent to a free labor society, which promoted hard work and industry, were absent in the South. The election of Lincoln highlighted the political imbalance and impending sectional crisis revolving around these issues.