5.6Expansion and its explosive question

The 1840s were gripped by "Manifest Destiny," the belief that the United States was destined to span the continent. The annexation of Texas and victory in the Mexican-American War (1846–1848) brought vast new territories, including California, into the Union.

But every new territory reopened an explosive question: would it be slave or free? The Compromise of 1850 patched over the crisis temporarily, admitting California as free while strengthening the Fugitive Slave Act. The compromise satisfied no one for long. Expansion had turned slavery from a regional institution into the central, unavoidable issue of national politics.