Dred Scott, Lincoln-Douglas, and John Brown

In 1857 the Supreme Court tried to settle slavery's spread once and for all in Dred Scott v. Sandford. It issued three holdings. First, Black Americans, free or enslaved, could never be citizens, so Scott had no right to sue. Second, Congress had no constitutional power to ban slavery in the territories, since that would deprive slaveholders of property without due process. Third, this meant the Missouri Compromise's slavery ban had been unconstitutional from the moment it passed. Instead of closing the question, the ruling seemed to nationalize slavery, since no territory could legally keep it out. The North was alarmed; the South was emboldened.

That same logic collided with Stephen Douglas's popular sovereignty in the 1858 Illinois Senate debates. At Freeport, Abraham Lincoln asked Douglas how a territory could still exclude slavery if the Court said Congress could not ban it there. Douglas answered that settlers could simply refuse to pass the local police laws slavery needed to survive in practice. This Freeport Doctrine satisfied Illinois voters but infuriated southern Democrats, who wanted federal protection for slavery guaranteed, not left to local whim. It split the Democratic Party heading into 1860.

John Brown pushed the crisis from courtrooms and debate halls into armed violence. In October 1859 he led a small interracial band to seize the federal arsenal at Harpers Ferry, Virginia, intending to arm enslaved people for a general uprising. He was trapped in the engine house, captured by federal troops under Robert E. Lee, tried for treason, and hanged. Southern whites saw proof that the North meant to destroy slavery by force, hardening the path toward secession.