It’s hard to imagine what 23,110 looks like. Make that the number of soldiers wounded, killed or missing after the bloodiest one-day battle in U.S. history, and it’s nearly impossible to fathom from our modern-day perspectives.

That’s why, on the first Saturday evening in December, volunteers set Antietam National Battlefield’s rolling hills ablaze with 23,110 candles in brown paper bags. The image — which visitors say makes the casualties far more than a statistic — is burned into the minds of those who’ve seen it during the event’s 25-year history.

Up to 3,000 visitors view the annual event by car, winding through the five-mile path that traverses the battlefield, said Keith Snyder, park ranger and chief of resource education at Antietam. (He recommends that visitors use the rest room before getting in the line, which can run up to two hours long.) The event starts at 6 p.m. and allows the last cars through at midnight.

Even more mind-boggling than the number of candles is the number of volunteers that help set them up each year.

Georgene Charles, founder and chairman of the illumination event, said that about 1,400 volunteers are registered through various groups — and many more show up that Saturday morning. She often has to turn people away and maintains a long waiting list.

Snyder said the illumination happens in December for two reasons: The time of year offers the maximum amount of darkness for the candles and it allows enough time for crops to be cleared from the fields. Two-thirds

of the battlefield’s 3,200 acres are leased out for farming each year.

It’s part of the park’s continual effort at authenticity, preserving the battlefield the way it looked when 11 families farmed and lived off of its land. The cornfields and hay are integral to that accuracy. (Snyder does admit that soybeans weren’t part of the mix in 1862.)

“You’re looking at one of the most well-preserved battlefields in the country,” Snyder said, taking in the view from behind the visitors’ center: grassy expanse that offers vistas of the farmland below with the Blue Ridge Mountains as the backdrop.

“That’s our mission, to make it look like it did the day of the battle.”

The National Park Service got a head start on that mission when the Army’s War Department recreated the battlefield scene in 1890 for training purposes. The department built a tower near Sunken Road for troops to better study the battle’s landscape, one that visitors can now ascend to get a bird’s-eye view.

Antietam was one of five battlefields, along with Gettysburg, that came under the care of the Army until the Park Service took over their management in 1933.

“There was a very early effort to preserve this,” Snyder said.

While Dec. 7 is the day the casualty numbers come to life, according to Snyder, “that’s

not the day to visit the park for a history tour.”

The park is devoted to preparations for the evening event that day and closed to the public — although there are plenty of other sites nearby to explore before or after the evening event.

Driving in from the south on a sunny July day, the concreteness of cities gives way to tree-lined roads dotted with historic homes and buildings.

From the road, the battlefield looks worth preserving simply for its natural beauty. Most visits to Antietam start at the visitors’ center, where a video orients its audience to the historical backdrop for the scenes, and visitors can link up with park rangers for more in-depth presentations. Most visitors see the battlefield by car, stopping at key locations along the way.

Tucked into the Cumberland Valley — called the Shenandoah Valley in Virginia — the battlefield is sandwiched between Antietam Creek and the Potomac River. It’s an idyllic setting for the story of how this ghastly battle unfolded on Sept. 17, 1862, one year into what would become a four-year war between the Confederate States in the South and the Union in the North.

Gen. Robert E. Lee’s first Northern invasion — an effort to decisively end the war by defeating the Union on its own soil — culminated here at the Battle of Antietam.

Lee had split the Confederate troops to keep his supply lines to Virginia open as he pressed north. About half of the troops accompanied Lt. Gen. TJ “Stonewall” Jackson to capture the Union garrison at Harpers Ferry, WV.

On Sept. 14, the first battle took place at South Mountain, a Union victory in which Federal soldiers outnumbered Confederates eight to one. But, the next day, 12,000 Union soldiers surrendered to Stonewall Jackson at Harpers Ferry, the largest surrender yet.

Lee started to gather his splintered army here, between Antietam Creek and the Potomac River, as Union soldiers gathered opposite the creek.

While there were twice as many Union soldiers as Confederates at Antietam, Union Gen. George McClellan had just three narrow bridges to get his 80,000 troops across the muddy creek.

“Antietam Creek, the Potomac River, all these waterways are just critical to the whole story,” Snyder said.

The 20– to 30-foot wide creek, filled with mud and underbrush, caused the Union troops to trickle in to the battle, making moot their numerical advantage over the opposition.

Along with the waterways, the general landscape of the battlefield defined the way it was fought. Lee was able to see from his high ground the 15,000 Union troops first attacking his left flank at dawn — and he turned his troops to face them as they emerged from “The Cornfield.”

Ten thousand were wounded at this first morning “slugfest,” as the Confederates used rifles to pick off soldiers emerging from the tall stalks.

Weapons had advanced since Americans fought the Revolutionary War, but the tactics used by both sides were largely the same. Rifles that could now shoot up to 400 yards accurately wreaked havoc on troops still standing in formation.

As they faced off in the second battle of the day at the Sunken Road, 3,000 Confederate troops used the aptly named road for protection against the 10,000 Union troops they faced.

“If you don’t see anything else, you’ve got to see Sunken Road,” says Snyder, noting that the name was changed to “Bloody Lane” after the battle. “It looks exactly like it did.”

That is, except for the bodies. The Battle of Antietam ended with around 4,000 dead soldiers strewn across the landscape and another 19,000 injured —an estimated one-third of which did not survive long. The casualties were almost evenly split between the two sides, although they represented a greater percentage of Confederate troops.

“At the end of the day, everyone’s about where they started,” Snyder said, noting that the better-known Battle of Gettysburg would later be waged as Lee’s second invasion of the North, and fought with similar goals to his first.

The Battle of Antietam greatly impacted the community in which it was fought. Ironically, “The bloodiest one-day battle in American history was fought in a community of pacifists,” Snyder said, noting that a community of Old German Baptist Brethren lived on these quiet farms. Physical scars and diseases were left behind, and “the community suffered terribly after the battle.”

Today, Sharpsburg is cute enough to lure visitors in for a leisurely lunch or pastry at the Mennonite Bakery not far from the battlefield and its cemetery (also worth a visit). Surrounding Washington County, MD, is home to five national and eight state parks along with 40 museums, as well as the city of Hagerstown.

History and quaint towns abound in the tri-state region along the Potomac River that was the backdrop for

an enormous amount of history — from the Civil War to Civil Rights.

South of Antietam and into West Virginia, Shepherdstown is a great option for a post-battlefield tour lunch, offering the variety of food associated with a college town (the Blue Moon Café is a good option) and plenty of museums and history to boot.

Continuing south, Harpers Ferry is a must stop, if only for the breathtaking views from the hills along the Appalachian Trail, with the Shenandoah and Potomac rivers meeting below.

Many stop at one of two outposts for the Jefferson County Convention and Visitors Bureau to get steered in the right direction before entering the small town.

“You can’t turn around and not see something historical going on,” said the bureau’s Shawn deLadurantaye standing in the entryway full of brochures on places like Charles Town, where John Brown was tried and executed for treason.

There is little in the way of parking, though, in this peninsula of a town. (A 30-minute stop doesn’t provide nearly enough time.) Parking is recommended at the Cavalier Heights visitors’ center,

which offers a shuttle service into the lower town.

Hike up the uneven stone steps near the end of the main street, past the remains of an old church, to see the view that Thomas Jefferson said was “worth the trip across the ocean.”

In nice weather, grab lunch with a view or almost any kind of ice cream at shops along Potomac Street and enjoy it on a walk across the footbridge over the Potomac River.

The region also offers an abundance of adventure sports, such as whitewater rafting in the river below or zip-lining through forest canopies.

Visitors can camp in a few places or stay at one of several historic bed-and-breakfasts.

In the winter months, Harpers Ferry and nearby towns dress up for “Old Time Christmas” celebrations. And, if you plan to be in town for the Antietam illumination on Dec. 7, you can catch a re-enactment of Captain Flagg’s 1864 Quartermaster City as 175 living history volunteers fill Harpers Ferry that morning.