The compromises that failed

The Mexican Cession forced Congress to face the slavery-expansion question again, and Henry Clay -- the same man behind the Missouri Compromise thirty years earlier -- brokered one more grand bargain: the Compromise of 1850. It admitted California as a free state, let the residents of New Mexico and Utah territories decide the slavery question themselves through "popular sovereignty," settled a Texas boundary dispute, and ended the slave trade (though not slavery itself) in Washington, D.C. To satisfy the South, it also included a much tougher Fugitive Slave Act, requiring citizens and officials even in free states to help capture and return escaped enslaved people, and denying accused fugitives the right to a jury trial.

Rather than calming tensions, the Fugitive Slave Act outraged many in the North who were now forced to participate directly in slavery's enforcement, and it radicalized opinion on both sides. Four years later, Stephen Douglas's Kansas-Nebraska Act (1854) organized the Kansas and Nebraska territories under popular sovereignty too -- effectively canceling the Missouri Compromise's old dividing line, since both territories sat north of it. Pro-slavery and anti-slavery settlers rushed into Kansas to try to win the vote by numbers, and violence broke out between them -- including the sack of the town of Lawrence and John Brown's deadly Pottawatomie Massacre in 1856 -- in a period so bloody it became known as "Bleeding Kansas," a preview of the larger war still four years away.