The document outlines several key events that increased tensions between the northern and southern states and contributed to the start of the Civil War. It discusses the Three-Fifths Compromise, the cotton gin's impact on the slave economy, the Missouri Compromise, debates around tariffs and states' rights, the Nullification Crisis, the Nat Turner slave rebellion, and attempts to compromise on the status of slavery in the territories gained from Mexico. These events highlighted disagreements over the expansion of slavery and states' rights that further divided the north and south.