If we are talking about “causes” of the Civil War that occur in a chronological order, we must be thinking about actual events that helped lead to the war. In other words, we cannot list slavery as a cause of the Civil War here (even though it was the major cause of the war) because it is not something that happened at some particular time between 1848 and 1860. What we are looking for, then, is three events. There are many possible choices, but here is one way to answer this question:
- The Kansas-Nebraska Act. This act threw the Missouri Compromise out the window, potentially opening Nebraska to slavery even though Nebraska was north of the line from the Missouri Compromise. This angered Northerners. Furthermore, the passage of this act led to the violence in “Bleeding Kansas” as Northern and Southern partisans rushed to populate the state so they could vote to make it free or slave.
- The Dred Scott decision. This Supreme Court decision made it impossible for any further compromise to be reached on the issue of slavery in the territories. It said that Congress had no right to pass laws saying whether a given territory could have slavery. This meant that every territory was up for grabs and a political solution would be much harder to arrive at.
- The election of Abraham Lincoln. When Lincoln was elected without any Southern votes, the South was convinced that it had lost all influence in the nation as a whole. This convinced many in the region of the need to secede.
All of these events helped to bring about the Civil War. They all worked to increase North-South animosity, to make compromise less possible, or both. With more animosity and less ability to compromise, war eventually became inevitable.