Timothy B. Wheeler / The Baltimore Sun

FREDERICK, Md. — Standing behind the old brick Worthington House, visitors can look down the gently sloping hillside and picture the Civil War battle that likely saved the nation’s capital from capture.

Much of the farmland where Union soldiers fought that hot summer day in 1864 to delay a Confederate attack on Washington has been preserved as Monocacy National Battlefield. But the view from the Worthington farm, where the fighting began, appears fated to become less historic.

A huge waste-to-energy plant is planned just across the Monocacy River from the 1,650-acre park — a project that has sparked criticism as the nation marks the 150th anniversary of the start of the war.

At 150 feet tall, with a 270-foot smokestack, the facility will loom over the trees that hide areas where Confederate cavalry forded the river to assault Union infantry.

“This will be visible from the visitors center and other key parts of the battlefield,” said Susan Trail, superintendent of the historic park on the southern outskirts of Frederick. “It will, in my view, overwhelm part of our landscape.”

As history buffs begin four years of events marking the anniversary of a conflict that continues to resonate in American politics and culture today, the land over which blue- and gray-clad soldiers bled and died is coming into increasing conflict with modern society. In Maryland, both the Monocacy and South Mountain battlefields face development pressures from energy projects.

Only about 20 percent of the land nationwide on which fighting occurred is preserved, either as national, state or local parks or in private ownership, according to the Civil War Trust, a nonprofit group dedicated to saving battlefields. Even the parks face encroachment by shopping malls, highways, housing developments, cellphone towers and casinos.

“A lot of this comes down to a clash between our modern needs and our sensibilities about preserving our resources,” Trail said.

Historic battle

Less famous than the bloodbaths that took place at nearby Antietam and Gettysburg, Pa., the Monocacy battle was noteworthy for the role historians say it played in thwarting the third Confederate invasion of the North.

On July 9, 1864, at a critical junction of roads and railroads crossing the Monocacy River, a hastily assembled Union force of 5,800 soldiers confronted a much larger Confederate army bent on attacking Washington, which at the time was lightly defended.

The South prevailed at the end of a daylong, seesaw battle that left 1,300 Union soldiers dead, wounded or missing. But the holding action bought crucial time for Union reinforcements to be rushed to the capital, and the invading army withdrew after finding its prize well-guarded.

The Monocacy park lies in the shadow of better-known Civil War clashes in the area. Authorized by Congress in the 1930s, it got no money to buy land until the 1970s and didn’t open to visitors until 20 years ago. The battlefield had long since been bisected by Interstate 270, built to connect Frederick with the Capital Beltway.

“I don’t think this would have happened today,” Trail said last week as traffic whizzed between the two farms where fighting raged. “It makes it hard for people to get a sense of the battle.”

But modern life keeps closing in: A high-tension power line from West Virginia that would have skirted the park has been put on hold — for now. Meanwhile, Frederick, the state’s second-largest city, has slowly sprawled southward toward the park.

“We’re this sea of green on the edge of the city,” Trail said.

The land across the river from the park has long been zoned for industrial use, though most of the facilities now are hidden by the trees lining the riverbank. That’s where Frederick County’s commissioners have decided to put the waste-to-energy plant.

Blaine Young, president of the five-member board, said he and the other commissioners are committed to building the plant, though he wishes it could be put elsewhere.

Another standoff

Not far to the west, Middletown-area residents are in a standoff with a Virginia-based company over another energy project. Some residents there fear that a natural gas compressor station proposed in their midst by Dominion Energy will spoil the rural, historic landscape at the foot of South Mountain.

The mountain was the scene of another relatively unheralded Civil War clash that proved to be the warmup for the bloodiest day of fighting in American history — the Battle of Antietam, where 23,000 on both sides were killed, wounded or missing.

Unlike Antietam, most of the South Mountain battlefield remains in private hands, though the state of Maryland has spent nearly $4 million to protect about 1,300 acres — most of it paying for easements obligating landowners not to develop their property.

Two years ago, though, Dominion bought 130 acres of unprotected farmland down the mountain from Fox’s Gap, one of the three sites where fighting occurred. On that tract is a historic stone house known as Fox’s Tavern: Union troops marched by the structure on their way to the fighting, and wounded soldiers were brought back there to be tended, say local residents. It’s currently occupied by a Dominion employee.

“This is all farmland out here,” said Elizabeth Bauer, whose home is a few minutes from the old stone house.

“We’re not against the energy infrastructure,” she said, “but we’re against using historic property and agricultural property. It doesn’t fit.”

Bauer and a few of her neighbors formed Citizens for the Preservation of Middletown Valley to rally the community against this and other perceived threats.

Dominion spokesman Charles Penn said the company is re-evaluating the project, which is meant to boost the flow of gas supplied via an interstate pipeline running through the area.