While the reasons for the Civil War are still debated by some, the primary reason for the war was the issue of slavery. For the South, slavery was a way of life and the base of an economic system that was fundamental to a great many prosperous Southern plantation owners. For the North, most especially among New England's abolitionists, slavery was an immoral and cruel institution that degraded an entire race of people and denied them even the most basic human rights. Thus, one of the most important objectives in teaching your students about the Civil War is to define, to the degree you deem best for the grade level, the motivations of both sides. Highlighting cultural differences is also a useful approach in explaining why northern and southern states were so divided on the issue of slavery. Also include a discussion of the differing economic systems of northern and southern states.
A discussion of the major engagements of the Civil War is another area you should cover in both your lecture and in the materials you provide. Important battles of the Civil War include Shiloh, Vicksburg and Gettysburg, which was a turning point in the war and a blow the South was never able to overcome. Visual aids can be extremely helpful to students in better understanding these engagements. Timetables and maps of the battlefields, along with photographs (a technology that was fairly new at the time) can also be helpful in engaging your students in the subject.
There were a number of important figures in the Civil War, from generals such as Ulysses S. Grant and Robert E. Lee to the national leaders Jefferson Davis and Abraham Lincoln. In addition to those major governmental and military leaders, there were people who in one way or another influenced them, including Frederick Douglass, Charles Sumner and Dorothea Dix. Have your students write short biographies of these figures based on the readings and lectures.
Today, proponents on both sides argue vigorously about the reasons for the war. Some Southerners contend that the war was actually more a result of a defense of "states' rights" than an issue of slavery. Some southern state buildings continue to fly the Rebel flag, as do many private individuals. For the descendants of slaves, the confederate flag is especially offensive and a painful reminder on an ugly part of the nation's history. Have your students hold a frank but respectful discussion of this issue.