One reporter will file from the Confederate side and another from the Union perspective, said organizer Marc Charisse, editor of the Hanover Evening Sun.
"We thought it would enhance people's understanding of what happened there," said Charisse, also a Civil War historian, who will be providing color commentary @esmcharisse.
York Daily Record editor James McClure will tweet the "big picture," Charisse said, an overview of the battle as the reenacted violence at Devil's Den unfolds.
There's no question that a few liberties are taken with the battle during the annual reenactment, which has attracted thousands of people to Gettysburg for decades. It is not fought on the actual battlefield (it's staged on a farm about seven miles away); it is often, as this year, not held on the battle's actual dates (July 1 to 3); and visitors pay $54 to watch the action over three days as an announcer provides the play-by-play.
Twitter, however, adds a new dimension of social media and instant communication for about 2,000 reenactors, who go to great lengths to replicate 19th-century warfare.
Do such modern intrusions push the bounds of authenticity for the reenactors, who dedicate themselves to executing exact troop movements, shouldering authentic armaments, and pulling off the period look right down to the buttons on their woolen jackets? (That's right, wool - even with Saturday's forecast for the Gettysburg area calling for 102-degree heat.)
Some historians say they don't mind adding social media to the picture, especially if it makes what was arguably the nation's most famous battle accessible to a new generation through the technology of the time.
After all, war correspondents in 1863, including those working for The Inquirer, filed dispatches using the latest mode of communication - the telegraph - sending out bulletins in the abbreviated language of the day: the dots and dashes of Morse code.
Today, anyone with a smartphone can stand on hallowed ground and peer into history as never before, said Charisse. The curious can find directions to obscure battlefield monuments and look up the history, on the spot, of military units and the officers who led them.
Michael Birkner, a history professor at Gettysburg College, likened live tweeting to You Are There, a 1950s CBS television program popular when he was a child.
"There would be Mike Wallace asking Stonewall Jackson at Chancellorsville, 'General, how does it look?' " said Birkner. "We want to be in the middle of the action. It's just a different technology from a different era."
Anthony Waskie, a Temple University German professor and Civil War aficionado, called it a "natural progression into new electronic media."
Waskie, who is portraying Union Gen. George G. Meade in the reenactment this year - as he has there and elsewhere since 1985 - said he supported "anything that gets the word out," though he admitted he has resisted social media himself.
"I don't tweet," Waskie said firmly.
Nevertheless, he thinks the general he portrays would be all for embracing technology. "Meade was an engineer and very much engaged in new innovations."
In fact, according to Charisse, Meade introduced a new way to gather and deliver battle data at Gettysburg. "The first thing he did when he arrived was ride his own line under a full moon with his cartographer, who had an easel on his saddle and produced maps of the Union positions," he said. "Then he distributed them to his corps commanders.
"When I told that story to a friend, he said, 'Oh, Meade, he won because he had the first mobile app.' "
Contact Amy Worden
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