Close quarters

In the opening sequence to the History Channel's latest documentary, Gettysburg, noise and smoke rise so thick through the air, Lt. Col. Rufus Dawes has to rely on moving the flag to signal his troops. While narrator Sam Rockwell explains that the flag, waving high and bright above the battlefield, is a magnet for enemy fire, the hands of the soldier holding it go limp with death, threatening to drop it.

Another pair of hands pushes forward and grasps the standard before that can happen. An instant later, they too go limp. In a matter of minutes, 10 flag bearers are killed in succession, but the hands keep coming and the colors never touch the ground.

It's a moving and terrible moment that proves from the outset that what we're watching is no dry history lesson. With executive producers Ridley (Black Hawk Down, Gladiator) and Tony (Top Gun, Unstoppable) Scott at the helm, the most significant battle of the Civil War is brutal, gut-wrenching, and personal. It's also enlightening in a way few documentaries are.

Part of the History Channel's four-year initiative to commemorate the 150th anniversary of the Civil War, the film uses talking heads and archival photography sparingly, relying instead on bloody reenactments, personal biography, and detailed CGI diagrams of battle plans and artillery.

The CGI effects are especially useful to newcomers to the Civil War specifically and to understanding military strategy in general. The reason and purpose for the fishhook formation employed by the Union is fascinatingly clear, as are the actions of the renegade general that endangered it.

Similarly, the short demonstrations of pioneering weaponry-like cannon balls that were really tin casings packed with 28 iron balls that would scatter on firing-help explain their devastating effect. And the effects are devastating, blowing apart 15 men at a time and wounding twice that number. The violence and brutality of the battles will be too much for young or sensitive viewers (at some points, blood splashes realistically across the camera lens), but it is less bloody than what you might see in an average PG-13 action movie.

Thanks to such innovations to the genre, Gettysburg has a gritty immediacy rare for Civil War movies, let alone Civil War documentaries. Even though we know the outcome of the battle, we feel the tension of each skirmish. And unlike most entertainment based on the period, director Adrian Moat never lets us forget the context for the conflict, highlighting the fact that slaves in the Gettysburg region took the opportunity of the battle to flee and that 150,000 slaves enlisted in the Union Army.

But the best thing about the film is the individual lives it explores. Along with Dawes, who went on to start a lumber business, become a congressman, and father a future vice president of the United States, the movie profiles various soldiers from all walks of life.

Their stories, some noble, some shameful, remind us that it was real men and not stern black-and-white daguerreotypes fighting for the future of our nation. And as we watch rank-and-file Union soldier Amos Humiston die clutching a photo of his three young children, we can't help but think of the fathers sacrificing themselves for the sake of their children today.

Though it premiered on Memorial Day, the History Channel will no doubt continue to run the two-hour film in heavy rotation until the anniversary of Gettysburg in July. This is good news as it gives viewers multiple opportunities to learn from that seminal moment in U.S. history. As Ridley Scott commented to the Associated Press about the Civil War, "It's wrong to say that war doesn't settle anything, because in this instance it did. It's a bit like why we keep doing movies about Nazi Germany. Because it should never be forgotten."