A line is made to separate free states and slave states.
People, typically Northerners, who not only disagreed with slavery but wanted black rights and the immediate end to slavery.
Dred Scott was a slave who's owner died while he was in a free state and he then moved to Missouri, a slave state, declaring that he was free. The case eventually got moved up to the Supreme Court when he sued and they decided that basically that he was still a slave.
The reason behind the South's attempt at Secession. Was thought to be an Abolitionist because he is a Republican.
The South, in an effort to secede, create the Confederate States of America to branch off into their own country. They select their president to be Jefferson Davis of Mississippi.
The Civil War was the war between the Union, or the United States, and the Confederates, or the Confederate States of America. It started when the South tried to secede to start a new, slave nation.