Before the Civil War, and for a short time after, sectionals was extremely present. In perhaps its most infamous manner - slavery and the restrictions put on black people all across the country. These restrictions forced several marginalized groups into small areas and forced them to bind together for protection.
In another example - petty sectionalism in the context of religious belief. The US was divided for hundreds of years by religion, which meant that the Union itself often fought over religion and religious values. Protestants in New England, Catholics in the south, and several other groups strewn throughout the regions.
If you visit the Senate chamber during a session on an average day, you're most likely to find the session presided over by "A. the majority leader" since the Vice President only comes in on special occasions.
Answer: The war was most defiantly worth it even if the lives of many were lost because the foundations of america were made from that specific war because it abolished slavery and preserved the Union/North. Which today is known as the Republican Party.
