Preservationists and a developer say they have worked out a deal that will protect a key portion of the Chancellorsville battlefield in Spotsylvania, a contentious issue that has tied up plans for the land for more than two years and led to a change in the county Board of Supervisors last fall.

The deal with Tricord Inc., a Spotsylvania developer, would preserve 140 acres of the battlefield. Many historians consider the battle in May 1863 the closest the Confederacy came to winning the Civil War, said Jim Campi, spokesman for the Washington-based Civil War Preservation Trust.

Most of that acreage, part of the roughly 790-acre Mullins Farm on Route 3 south of Fredericksburg, would have been developed under a proposal that met with widespread opposition in March 2003. County residents came out in droves to protest plans by Reston-based Dogwood Development Group to build 2,000 homes and 1.2 million square feet of commercial development along one of the most congested roads in one of the fastest-growing counties in the nation.

When the Board of Supervisors rejected the project as too large, preservationists continued trying to buy the farm to stop development but said they were thwarted when owner John Mullins demanded $40 million for land assessed at about $5.6 million. Mullins has declined to give details of the negotiations, saying only that preservationists did not tell the truth about them.

Mullins recently sold 566 acres of the farm to Toll Bros., a national developer that plans to build 162 homes. Tricord is under contract to buy the rest for $12.5 million, according to Tricord co-owner Mike Jones.

Under the deal reached with preservationists, Tricord would cluster 294 homes for senior citizens on about 87 acres and sell the remaining 140 acres to the Preservation Trust for $3 million, according to Jones and Campi.

"This is unquestionably one of the most important deals we are involved in. This was a national issue," Campi said. The trust plans to turn the land into a tourist destination with interpretive trails and signs.

Jones, Campi and supervisors Chairman Robert F. Hagan (R-Courtland) -- who represents the district where the farm is located -- say the deal is sealed, but it requires a rezoning and thus must pass the entire board to take effect. Hagan and Supervisor Henry Connors Jr. (I-Chancellor) said that all board members have seen the plan and that he expects the rezoning application to be approved easily.

The Chancellorsville site has been controversial since the initial project was proposed. Two supervisors who supported the larger development, saying it would bring precious commercial development to Spotsylvania, were voted out last November.