When did sectionalism start and why?

By the 1850s sectionalism bitterly erupted over the issue of slavery and state's rights culminating in the American Civil War (1861–1865). American loyalties to their section overshadowed loyalty to the nation.

So, why did sectionalism develop in the United States?

In the United States. Sectionalism in 1800s America refers to the different lifestyles, social structures, customs, and the political values of the North and the South. Historians have debated whether economic differences between the industrial Northeast and the agricultural South helped cause the Civil War.

What is the definition of sectionalism in history?

Definition of sectionalism for English Language Learners. : a tendency to be more concerned with the interests of your particular group or region than with the problems and interests of the larger group, country, etc.