The term "slavery's expansion" refers to the territorial and political conflicts that arose as the United States expanded westward, particularly regarding whether new states would allow or prohibit slavery.
Related terms
Missouri Compromise: An agreement in 1820 that admitted Missouri as a slave state and Maine as a free state to maintain the balance between slave and free states in Congress.
Kansas-Nebraska Act: A law passed in 1854 that allowed popular sovereignty (allowing residents to vote) on the issue of slavery in Kansas and Nebraska territories, leading to violent clashes between pro-slavery and anti-slavery supporters.
Dred Scott Decision: A Supreme Court ruling in 1857 that determined enslaved individuals were property with no rights, which further fueled tensions over the expansion of slavery into new territories.