Introduction to the Civil War: Causes and Key Developments: Discussion of slavery on Southern States plantations as a major cause of the American Civil War. Underground Railroad as an escape mechanism for slaves. Role of Harriet Tubman as a leader in coordinating the Underground Railroad movement/refuge of slaves to the northern states. Dred Scott case as rejection of an escaped slave freedom after moving to a northern state. Breakout of Civil War in Ft. Sumter South Carolina in 1861. Video on the Civil War developments.