Housing developers today have replaced the sharp-shooters scouring the rolling hills around the Gettysburg battlefield.

Tourists visiting the formal rose garden outside the 22-room Greek revival mansion called Oatlands in Leesburg could soon be watching 277 families grilling dinner on their backyard decks in a proposed housing development nearby.

And Monticello officials are seeking to reverse a steady erosion in the number of visitors making the pilgrimage to President Thomas Jefferson's storied home.

These are among the issues confronting a grass-roots coalition that is seeking to preserve and promote the 175-mile long swathe of land along Route 15, the Old Carolina Road, a rural crescent that stretches from Gettysburg in Pennsylvania to Monticello in Virginia. It's a region that's squarely in the path of Washington's dynamic westward suburban expansion, where eager home buyers are flocking to buy affordable homes for their families.

But the preservationists, who have dubbed the effort the Journey Through Hallowed Ground, after President Abraham Lincoln's famous words after the Gettysburg battle, think they have found a new tool: They are seeking to have the region named a national heritage area, a relatively new and increasingly popular designation created by the National Park Service.

Local boosters say the heritage area designation will increase the chances of preserving the region's rural feel, draw new tourism to the area and help its numerous historic sites market themselves more effectively.

But the effort has also drawn opposition from vocal property rights advocates such as J. Peyton Knight, executive director of the American Policy Center in Warrenton, who has testified against national heritage areas in the past. "These designations choke off entire areas from the necessary housing development and community development they need to sustain themselves," he said.

This fall, U.S. Rep. Roscoe Bartlett (R), whose Western Maryland district straddles that state's portion of the region, plans to introduce legislation that would create the new heritage area in the House of Representatives. A similar bill is to be be sponsored in the Senate, Bartlett said.

The Journey contains an awesome cluster of historic sites, encompassing six presidential homes, including Thomas Jefferson's Monticello, James Madison's Montpelier, James Monroe's Oak Hill and Ashlawn Highland, the Dwight Eisenhower cottage in Gettysburg and President Zachary Taylor's birthplace in Virginia. Other famous dwellings housed Chief Justice John Marshall and Gen. George C. Marshall, who in his Leesburg house drafted the Marshall Plan to help Europe recover after World War II. Camp David, meanwhile, remains a favorite presidential getaway spot.

The region also contains the largest collection of Civil War battlefields: Not only Gettysburg, but also Antietam in Maryland and Manassas, Chancellorsville, the Wilderness and Cedar Mountain in Virginia, as well as sites of many smaller skirmishes.

"No other land in America has been more fought over," said Cate Magennis Wyatt, executive director of the Journey, a Waterford resident who helped develop the Lansdowne project in Loudoun County and who served as state secretary of commerce and trade in the administration of Virginia Gov. Doug Wilder (D).

National heritage areas are a 20-year-old Park Service device that does not restrict land uses the way a national park does, but rather allows regions to collaboratively market themselves under the Park Service name, organize themselves as heritage tourism destinations and help inspire a sense of regional cohesion. The designation has little immediate effect on homeowners. It has, however, been effective at helping regions raise money for marketing programs that boost tourism and at sparking expansion of home-grown businesses such as restaurants and boutiques.

By definition, heritage areas are regions unified by a unique and specialized historic legacy. The Blackstone River Valley National Heritage Corridor in Massachusetts and Rhode Island, for example, contains the remnants of America's earliest industrial history, including the Slater Mill where the textile industry took root in the early 1800s. The Lackawanna Heritage Valley, near Scranton, Pa., chronicles the contribution of anthracite coal mining to America's economic expansion.

"You take the centerpiece of a region's history and you build your present and future around it," said John Cosgrove, executive director of the Alliance of National Heritage Areas.

Unlike National Park Service properties, national heritage areas remain privately owned, except for specific historic parcels subject to individual designation. They get a relatively small amount of federal funding -- $400,000 a year on average, but up to $1 million, or $10 million over 15 years -- but are expected to become financially self-sufficient and promote some limited economic development, such as restaurants and hotels. They usually have visitor centers that help tourists find their way from spot to spot and they boost community organizing efforts for preservation projects. Heritage areas also get technical advice and support from Park Service officials.

The first area, the Illinois & Michigan National Heritage Corridor, which highlights the 97-mile canal that linked the Chicago River near Lake Michigan to the Illinois River and thus transformed Chicago into a global powerhouse, opened in 1984. After two decades, there are now 27 such areas, mostly in the Northeast.

One of the closest heritage areas is the Shenandoah Valley Battlefields National Historic District, based in New Market, Va. That is also the only heritage area that has been allowed to purchase land with federal money. It makes its purchases cautiously, said Howard Kittell, executive director.

"We only purchase land from willing sellers; there's no condemnation; and we purchase at the market price," he said.

The success of national heritage areas is spawning more of them. Last month the Senate authorized 10 more heritage areas, including three in the South and four in the West, and the House of Representatives is expected to vote on the package of properties in the fall.

"Like nuclear fission, these things produce a lot of energy," said Brenda Barrett, the Park Service's national coordinator for heritage areas, adding that heritage areas "bubble up" from communities and prosper with local support.

"The South is aflame with proposed heritage areas," with more than a dozen more sites under consideration there. Meanwhile, the sites in the West that are being proposed are so large that the acreage designated "would triple because of the size of the western heritage areas," Barrett said.

Supporters of the Route 15 heritage area see the effort as a key step toward salvaging the community's soul before it disappears under pavement and townhouses ribboned by overcrowded highways.

"We're on the way to extinguishing the character -- on the way to extinguishing the sense of place," said Robert Lowe Nieweg, director of the Southern Field Office at the National Trust for Historic Preservation. That group last month put the Routre 15 corridor on its annual list of most endangered places.

"It matters to people who live here but it matters to the nation as a whole. . . . Many [historic] parks are ending up as islands of green amid suburban sprawl. The sites are secured but the setting is evaporating."

Supporters say the heritage area designation would have no impact on zoning, and that any limitations on development that might occur would happen only voluntarily, perhaps as conservation easements granted to the states in exchange for tax credits, or by community agreement. Any land-preservation that occurs would be voluntary on the part of the land owners, supporters say.

"It's all honorific and self-selection," said Wyatt. "It's completely voluntary. . . . There are no regulatory overlays on land use."

Some local residents are applauding the efforts. Frank S. Walker, whose family has lived in the area since the 1700s and who conducts historic tours of the area around Orange, is disgusted with what is happening to the still-rural area, which has become a housing mecca for people who work in Charlottesville and Fredericksburg.

"We're in the process of paving it over, pulling it down and selling it off -- and a lot of it has already happened," said Walker, who has arranged to place his 242-acre family homestead in a conservation easement. The Piedmont Environmental Council, based in Warrenton, which is also participating in the Journey effort, is seeking to woo other property owners into putting their properties under easements in exchange for federal income tax deductions and state tax credits.

But the effort to promote the Old Carolina Road as a heritage area is being launched in the face of a burgeoning and strengthening property rights movement, with growing numbers of people worried about governmental entities seeking to control other people's land. The property rights movement has been galvanized in the wake of the Supreme Court's June decision on Kelo v. New London, where the New London, Conn., government had sought to acquire homes through eminent domain to build a waterfront hotel and office complex. The Supreme Court ruled 5-to-4 that the government be permitted to continue with its plan. Several state legislatures have rushed to enact legislation to prevent similar urban development projects within their borders.

Knight, the property rights advocate, runs his office out of an old brick building in downtown Warrenton, directly on the Journey's route. He says that although he too loves historic structures, government intervention in land use is problematic. He worries a national heritage area designation would be an opening wedge toward new regulations along the Route 15 corridor.

"More and more often we're seeing historic preservation and cultural preservation being used by ideologues within the environmental and historical community to cordon off massive amounts of land and deny the people in those regions the ability to grow and bring commerce into their communities," Knight said.

Knight worries that preservation activism could lead to more land restrictions. "Certain core areas are historically significant, and then not only those are deemed untouchable but also the buffer zones are also cordoned off. Then buffer zones on the buffer zones and so on," he said.

In a report issued last year, the Government Accountability Office said it could not find a single example nationwide of a heritage area affecting private property values or use, although the report added that the designations encourage local governments to adopt land-use policies "consistent with the heritage areas' plans," which could "indirectly influence zoning and land use planning."

In its efforts to underscore support of private property rights, the Senate bill passed last month authorizing the new heritage areas contained language that said the bill should not be construed to "modify, enlarge or diminish any authority of federal, state or local governments to regulate any use of privately owned lands," or to permit any local coordinating entity "any authority" to do so.

Bartlett, a political conservative, bristles at criticism from property rights advocates.

"I'm a big, big property rights supporter, and nobody who knows me can question it," Bartlett said.

But Knight is unconvinced. He said heritage areas are ill-disguised political "pork" because of the federal money they bring.

"Congressmen see them as pork they are delivering to their constituents. Republicans and Democrats are equally terrible on this issue. . . . It cuts across party lines because everybody likes pork," he said.

One land-use issue that heritage areas clearly seek to address -- a problem that this 175-mile trek particularly confronts -- is the number of jurisdictions that operate independently, often communicating poorly with neighboring governments and jealous of local prerogatives. The problem is compounded for the Journey area because it encompasses three states, a dozen counties and many towns and cities.

"There's not a tradition of cross-jurisdictional planning," Nieweg said. "There's no regional land-use planning."

In Adams County, Pa., for example, where Gettysburg is located, there are 34 separate municipalities, 13 boroughs and 21 townships with land-use authority. Developers have proposed 60 housing projects in those jurisdictions. They would result in up to 14,000 housing units, dwarfing and overwhelming the borough of Gettysburg, a small town of 7,000 surrounded by battlefields, said Richard H. Schmoyer, director of the Adams County Office of Planning and Development. Schmoyer said it is essential the county improve coordination among jurisdictions, and he hopes a heritage area designation would help it do so.

"We're talking about a swathe of urbanization here, not suburbanization," he said. ". . . These projects are huge. The traffic alone would have enormous implications."

Further south along Route 15, at Oatlands, a plantation owned and managed by the National Trust for Historic Preservation, a 277-home subdivision is moving forward. The homes will be built across the ridge from Oatlands, with new homeowners enjoying the views of the mansion's ornamental rose garden, where historic plant varieties are carefully labeled and visitors stroll under lush trellises, meandering on oyster shell pathways.

"People will pay $800,000 for homes in our viewshed and it's hard to welcome that," Nieweg said. "A large part of their value is what they can see from our investment."

Nieweg and other preservationists would like to raise awareness of the issues -- and money to buy properties that become available. He hopes a heritage area would help that goal.

Even officials at Monticello, which has been able to protect much of the landscape surrounding the famous home of Thomas Jefferson, the nation's third president and drafter of the Declaration of Independence, think inclusion in a heritage area might be a way to promote the property. Visitation there has dropped to 1 percent to 6 percent each year for the past seven years.

"We've had a slow but perceptible decline in attendance," said Kat Imhoff, vice president for planning and facilities at Monticello. "We see the Journey as another way to spread the word."

Cate Magennis Wyatt, executive director of the Journey Through Hallowed Ground