- The Northern half of the U.S. was also known as the New England section and was more industrial than the South. The North was heavily dependent upon the non-agricultural economy to survive. However, the South was primarily agricultural and almost completely dependent upon slave-labor to grow the ever-profitable crops of cotton and tobacco. Feeling threatened by population loss due to Western migration of many people and the growing strength of the South, the North grew increasingly opposed to slavery.
- Tensions between the North and South became even more complex when Western territories were expanded. Many Southerners migrated further west and brought slaves with them. The North felt the increasing pressure and competition from the South and Western regions, which were pro-slavery and gaining more political leverage as their economies grew substantially. Questions of economy, slavery and Western migration finally reached a tipping point and resulted in the Civil War.
- After no agreements could be made, the South seceded from the nation. For four years, the nation was divided against itself, and at the center of the tension was the matter of States' rights versus control by a federal authority. After the Civil War, the federal government asserted more control over the different sections in order to avoid a similar outbreak of violence from happening again in the future. This set a precedent, which challenged lawmakers with finding a balance between States' rights and federal authority.
- With continued immigration and Westward expansion, American attitudes towards sectionalism began to change as more left smaller towns and opted to migrate to larger cities in search of work. The Industrial Revolution and other advances in technology made it more attractive for workers to leave the fields and work in factories. Scores of new immigrants arrived in the late-19th and early-20th centuries. Sectionalist attitudes waned in favor of the larger American identity.