What battle of ideas characterized the buildup to the Civil War, and how did each side define liberty for themselves?

What battle of ideas characterized the buildup to the Civil War, and how did each side define liberty for themselves? Also, what were Northern attitudes toward black troops, and how did their participation help reshape the idea of liberty?

Please be sure to answer the questions with detailed answers in your own words, with any sources used properly cited. There should be one main post (of about 300 words) that directly addresses the assigned question and two substantial responses (about 100 words each) to others posts. Each discussion’s main post should be completed by Wednesday of each week; responses to others’ posts should be completed by Saturday.