- The North, South, and West developed very differently economically and socially in the early 1800s. The North industrialized while the South remained agricultural and relied on slavery. The West was focused on farming, fur trapping, and real estate speculation.
- These regional differences led to conflicting political interests around issues like tariffs and the expansion of slavery into new territories. The Compromise of 1850 temporarily resolved some of these issues but reinforced the concept of "popular sovereignty" that exacerbated tensions.
- The Kansas-Nebraska Act repealed the Missouri Compromise, effectively opening Kansas and Nebraska to slavery and sparking violent clashes known as "Bleeding Kansas" that further divided the North and South. This