The country had become divided when war broke out and more than 700,000 Americans died during what some still call the War Between the States.

Its stories include the battles at Bull Run, Antietam and Gettysburg. However, stories of battles and the people who fought them in what was known then as “the West” have been scant.

“One of the reasons the Western Theater didn’t get a lot of attention is that there is not a lot of photo history,” said Chris Wheeler, the producer and director of “Civil War: The Untold Story,” a five-part series focused on the battles between the Appalachians and Mississippi River.

More photographical evidence of the war  in and around Washington, D.C. exist, Wheeler explained, because photographers didn’t go west to shoot pictures, “but just because there weren’t a lot of photos doesn’t mean it wasn’t important,” he said.

Wheeler’s documentary, narrated by Elizabeth McGovern of the hit British period drama Downton Abbey, is set to air on PBS beginning April 20. For locals, the third installment of the five-part series, titled “River of Death” and centered on Vicksburg, will be screened at 7 p.m. Thursday at the Southern Cultural Heritage Center.

The documentary will include stories of Shiloh, Vicksburg, Chickamauga, Atlanta and other battles in the Western Theater, Wheeler said.

“Many historians believe that the Western Theater was where the war was won and lost,” he said.  “The five-part series will also provide new insights into the relatively unknown roles African Americans played in the conflict — from enslaved to emancipated to soldier,” Wheeler said.

Wheeler said he worked closely with the National Park Services in gathering information for the documentary and interviewed more than a dozen of the nation’s top historians. That list includes Henry R. Luce, the professor of the Civil War era at Gettysburg College, Robert C. Fluhrer, the professor of Civil War studies at Gettysburg College, Amy Murrell Taylor, an associate professor of history at the University of Kentucky and Stacy Allen, the Chief Historian at Shiloh National Military Park.

“This is one of the best documentaries I’ve seen on the Civil War,” said retired Vicksburg National Military Park historian, Terry Winschel, who was also one of the historians contacted by Wheeler.

“Chris and his crew were very conscience about what they were doing.  Most people have a very shallow knowledge of the Civil War and this film will help broaden their views. Operations in the West get short changed,” Winschel said, “and this film also puts more emphasis on Vicksburg’s role in the Civil War and it helps promote Vicksburg, which is great.”

Wheeler said many of the scenes were filmed on the same grounds where the battles were fought, including Vicksburg National Military Park and Raymond Military Park.

The documentary had been in the making “on and off” for about five years, “longer than it took to fight the war,” Wheeler said. It touches on the causes of the war, the home front, the politics of war, the impact of war on Southern civilians and women and chronicles Lincoln’s 1864 presidential campaign.

“Lincoln said Vicksburg was the key to the South, which just speaks to the importance of the area,” Wheeler said.

Henry R. Luce, the professor of the Civil War era at Gettysburg College, Robert C. Fluhrer, the professor of Civil War studies at Gettysburg College, Amy Murrell Taylor, an associate professor of history at the University of Kentucky and Stacy Allen, the Chief Historian at Shiloh National Military Park.

“There is a power to this story of a time when we fought each other and our government, but the film is not just about who we were then. It’s about who we are now. In a nation arguably as divided today as we were 150 years ago, Civil War: The Untold Story is a compelling, relevant program that we believe will strike a powerful chord with Americans today,” said Wheeler.

The film is produced for public television by Great Divide Pictures, which, in addition to numerous cable television documentaries, has created more than 25 films shown in national park visitor centers nationwide.

If you go

Vicksburg National Military Park will host a preview screening of “River of Death,” episode three of a five-part documentary entitled “Civil War: The Untold Story” at 7 p.m. Thursday at the Southern Cultural Heritage Center, 1302 Adams St. For more information, call 601-631-2997, 601-636-0583 or visit www.nps.gov/vick. The show will air at 5 p.m. Sundays on PBS starting April 20.