"The civilians living there have done careful research of the residents of the town and they have taken on their identities, including their trade and craft," said Shelton.
Safety of participants and guests comes first, but authenticity also is a priority.
"People are here to recognize and honor and commemorate what these people went through, the sacrifices of both soldiers and civilians," said Shelton.
The battles draw re-enactors devoted to donning the proper uniforms and equipment. They can get caught up in the heat of the battle and emotional or significant moments.
"That intensity is something that really sparks re-enactors," she said. "That combined with leaving electronics and the modern world behind."
Visitors and participants alike understand that real people died in battle -- that freedom had a cost.
Making the battlefield historically accurate
While battle re-enactments are not permitted on National Park Service sites -- the commemorative clashes will be on privately owned land -- such events and the visitor experience at Gettysburg National Military Park are "not mutually exclusive," said Litterst.
"We want that excitement to spill over to the sites and grounds where the events actually took place," he said.
The National Park Service does not provide crowd estimates or projections, but it's clear the park will be busy over the next week, given ranger-led hikes and special programs.
"We will probably see crowds we probably haven't seen before, or since the centennial," said Litterst. "For the next couple weeks, there won't be many places to get some alone time here."
But for those who want to get away from at least some of the hustle and bustle, he recommends a visit to the East Cavalry Battlefield Site east of town and the park's Big Round Top, which has a great walking trail.
The battlefield looks much different from even 20 years ago as the NPS worked to make it look much closer to its 1863 appearance. Trees have been removed in some places and orchards planted.
Thousands may make the July 3 Pickett's Charge commemorative march, timed to the actual assault.
Those with younger legs may be in front. And, like battles of old, there will be stragglers.
"There will be not be a shortage of people with stories and pictures of great-great grandfathers who made that march," said Litterst. "That is a neat part of the story."