We're privileged to own the History Channel's America: The Story of Us DVD series, and my older kids find it fascinating. Their portion on the Civil War can be accessed online in segments beginning here.
Typically, the History Channel's videos have what I would dub a PG-level of violence: a gun being shot and a person falling back, for example, but little to no blood. This particular Civil War portion was a little more graphic than most due to the discussion on the Minie Ball, subjects like amputation, etc. (It was, after all, a war.) Be aware. But my oldest found it intriguing, and it certainly helped to bring all the pieces together. Perhaps some of the lesser violent portions, like Lincoln's War Machine would be more acceptable to younger or more sensitive viewers (it's expensive for me to stream video where I live, so please view it for your own discretionary purposes).