Your students will have a formal debate on issues that were either part of the Civil War, led up to the Civil War, or exist today but stem from the Civil War. This week-long activity is bound to ramp up your classroom discussions. I have done this type of activity for 15 years and look forward to it every time it comes around.
This website gives some sample pages from the book, 50 Debate Prompts for Kids. I liked this because the book first teaches the basic guidelines and reasoning for debates, then equips the teacher with potential topics and how to teach them. This would be useful in any grade classroom because you can adapt the ideas for the different levels, but the objectives for debates stay the same.