Gettysburg. Manassas. Antietam. Vicksburg. Chickamauga. Kennesaw Mountain. Atlanta.

What do these places have in common? All were sites of major Civil War battles, and each — except Atlanta — has been preserved as a national park that history enthusiasts can visit and see, much as they looked in the most costly war in American history.

Each — but not Atlanta — has a thriving tourist industry catering to history buffs.

But starting June 18, you’ll be able to “see” important sites of the Battle of Atlanta and “feel history like you can at Gettysburg” thanks to a new web-based app developed by a team led by Emory University history professor Allen Tullos and Daniel Pollock, a medical epidemiologist at the Centers for Disease Control and Prevention. It’s being unveiled and demonstrated 7 p.m. June 18 at the Cyclorama.

It’s not the kind of app that can be downloaded, but can be accessed via smart phone by inserting the URL battleatl.org in any browser.

“Most important battle sites in Atlanta are covered over with roads or buildings,” said Pollock. “With this new app you can visit sites thousands drive past every day but don’t even know. The app will have maps, vintage and new photographs of each area, brief explanations, and will orient you to the next location, and there are 12 stops. Also, pictures of generals involved at each spot. One image is of a Confederate Memorial Day ceremony from 1881 that appeared in Frank Leslie’s Illustrated Newspaper, a major periodical of the time.”

The scholars recommend the app be used in auto tours that involve at least two people, one to eyeball a smart phone and the other to drive. A tour will take three to four hours.

Most people don’t know, Pollock said, that the battle started near the spot where Alonzo Crim High School is located in East Atlanta, not far from where Union Gen. James McPherson was killed. Other tour stops include the Carter Presidential Library, where Union Gen. William T. Sherman set up field headquarters, Oakland Cemetery, Rebel Gen. John Bell Hood’s observation post, a Confederate fort at Grant Park, Leggett’s Hill at Moreland Avenue and Interstate 20, the most strategic position in the battle, and Degress Avenue, site of the most famous moments in the struggle, and the point from which the first Union shells were fired into downtown.

Besides brief explanations at each site, the app will allow viewers to click on a lengthy essay, telling the whole story of the campaign.

The rollout of the app is being held at the Cyclorama because “much of the battle circulates around that space and we used images of the painting in the app,” Tullos said. Each stop also will have a video, featuring Pollock talking about what happened there.

“It has maps, guides you from one stop to another, has photographs, text, video, and orients you so you’ll know where you are,” he said.

Why so much work when his “day job” keeps him occupied?

“I want to understand Atlanta’s place in history,” he said. “What happened here led to Lincoln’s re-election and was a turning point in history.”