Final answer:
Sectionalism is the increased feelings of pride and devotion to their region within a country. In the United States during the 1820s, sectionalism grew as politicians became divided over the interests of the regions they represented. The Missouri Compromise played a role in the eventual abolition of slavery.
Step-by-step explanation:
Sectionalism refers to the increased feelings of pride and devotion that citizens develop towards their own region within a country. During the 1820s in the United States, sectionalism grew as politicians became divided over the interests of the regions they represented. This division was particularly evident in debates surrounding the admission of the State of Missouri in 1821. The Missouri Compromise, which aimed to maintain a balance between free and slave states, contributed to the eventual abolition of slavery by highlighting the divisive nature of the issue and intensifying sectional tensions.