Manifest Destiny: The belief that it was America's destiny to expand its territory from coast to coast, which fueled westward expansion during the antebellum period.
Sectionalism: Loyalty or support for one's own region or section of the country rather than for the nation as a whole. This division along regional lines contributed to conflicts leading up to the Civil War.
Compromise of 1850: An attempt by Congress to address sectional tensions over slavery through a series of legislative measures that included allowing popular sovereignty in some territories and strengthening fugitive slave laws.