From the Republican perspective, the Kansas-Nebraska Act, the Brooks-Sumner affair, the Dred Scott decision, and the Lecompton constitution amounted to irrefutable evidence of the South’s aggressive promotion of slavery. White Southerners, of course, saw things differently. They were the ones who were under siege, they declared. They believed that Northerners were itching to use their numerical advantage to attack slavery, and not just in the territories. Republicans had made it clear that they were unwilling to accept the Dred Scott ruling as the last word on the issue of slavery expansion. And John Brown’s attempt to incite a slave insurrection in Virginia in 1859 proved to Southerners that Northerners would do anything to end slavery.

Talk of leaving the Union had been heard for years, but until the final crisis, Southerners had used secession as a ploy to gain concessions within the Union, not to destroy it. Then the 1850s delivered powerful blows to Southerners’ confidence that they could remain in the Union and protect slavery. When the Republican Party won the White House in 1860, many Southerners concluded that they would have to leave.