In a dignified brick church that pulled duty as a field hospital during the Civil War, more than 165 people gathered to plan for the second battle for Unison. Although the tiny hamlet has fewer than two dozen houses in its historic district, the people who live in the area responded in force to a call for recruits to fight an entity often perceived as the enemy in western Loudoun County: the developer.

JR Gould Enterprises, a Purcellville development company, has bought 90 acres just outside the crossroads of Unison and plans to build as many as 28 houses there. The site includes some of the highest-elevation land between Middleburg and Mount Weather, and new homes built on the ridge will be visible for miles.

Under the county's previous planning laws, the land around the 18th-century village was zoned for one house per 50 acres, but that restriction was overturned by the Virginia Supreme Court in March. New land-use laws, which are likely to allow a maximum of four houses on the site, are not expected to be enacted before the end of the year or early next year. Meanwhile, zoning laws that allow three-acre lots are in effect, and developers, such as JR Gould Enterprises, have moved to take advantage of the opportunity.

As the crowd slipped into the pews of the 1832 United Methodist Church on Sunday night, they saw slides of a Unison "before" and "after" the proposed Bloomfield subdivision. Before: picturesque stone walls; scenic vistas; rustic, unpaved roads; and the kind of board fencing that spells h-o-r-s-e. The envisioned "after"? Traffic, blacktop, turning lanes, McMansions.

Developer Jeff Gould said Tuesday that his development would not be out of proportion to its setting. But Paul Hodge, president of the Unison Preservation Society, said the "subdivision will overwhelm our small village."

The preservation society was formed in 2001 to create a historic district in Unison and to save and restore the 1880 general store at the village crossroads. Both campaigns were successful. Last month, however, the society decided it needed a public membership to fight the Bloomfield development, and in just a few weeks, it signed up 176 members and raised a war chest of $25,000. About 55 more people joined the society after the Sunday night meeting and pledged an additional $8,000. The society has hired a lawyer and a team of engineering experts to scrutinize the project -- including its septic systems and wells and its affect on traffic and historic values. The society also has done an independent wetlands analysis of the site.

"This is not a done deal," Kim Hart, a 20-year resident of Unison and a member of the society's board, told the crowd. "We have the brains, the resources and the collective will to stop this project."

Hart vowed that the society would monitor every step in the development process. Every two weeks, he said, it would file a Freedom of Information Act application with the county so that it keeps apprised of all developments. Test wells are about to be drilled at the site, and the group plans to monitor wells on properties adjacent to the project to see if their water supplies are compromised. Gould promised that if anything done at the subdivision site affects a neighboring well, "We will drill them [the neighbors] another well."

The society's goal is to use all legal means to delay the project until the new zoning laws come into being and to stop any move to grandfather the project.

Gould said that his project will conform to all state and county standards. "I won't be cutting any corners," he said. "With all the growth in Loudoun County, you can't freeze this little section. It doesn't work. People like to live on beautiful land."

But residents like Terri O'Dowd and Joyce Scheuermann moved to the Unison area precisely to get away from development. We were "escaping Fairfax County," said O'Dowd.

Laurie Fenton and her husband, Chris Ambrose, who is vice president of the society, live next door to the old church, where graffiti scratched by wounded Civil War soldiers into the upstairs walls is still visible.

Fenton summed up the atmosphere in the church on Sunday night: "No matter how uphill a battle," she said, "we're going to give it 120 percent."

Many people signed up Sunday to join the Unison Preservation Society.