The abolitionist raid by John Brown on Harper's Ferry provided extra and necessary tension against the South and North so that they wouldn't accommodate each other’s' wishes further.
The election of Abraham Lincoln allowed for Lincoln to establish his stance unification of the Union and the Confederacy. During his tenure, he would do many great things such as drafting the Emancipation Proclamation, which would proclaim freedom for the slaves in the ten rebellious states.
This event played a huge role in defiance against the North who were against slavery, and the South seceded in order to preserve