A 322-acre tract of rolling hills, which an official called the "iconic centerpiece" of his Chester County town, has been in developers' sights for decades, and could soon sprout nearly 400 housing units under plans that Toll Bros. has proposed.

Westtown Township's comprehensive plan from 15 years ago acknowledged that Crebilly Farm would inevitably be developed, said Richard Pomerantz, chair of the local planning commission, but he said former municipal leaders had not planned adequately for what development would best fit the town of about 11,000.

"I wish we weren't here and didn't need to be here," Pomerantz said to more than 200 people gathered in a middle school auditorium Wednesday night for the first of four planning commission meetings to discuss the Toll project. "The seeds of today were sown a long time ago."

Chester County is one of the state's fastest-growing counties, leading municipal officials to wrestle with how to handle that population growth while also preserving the open space that government officials and residents consider a hallmark.

More than 3,500 people in and around Westtown have signed an online petition against the development of Crebilly Farm, bordered by Route 202 to the east and Route 926 to the south. Residents cite worries that are common when developers set their sights on open land: congested roads, overcrowded schools, loss of green space.

Residents say the property's proximity to the Brandywine Battlefield and the possibility that troops crossed the farm should give the developers pause. Eugene Hough, cofounder of the group Saving Hallowed Ground, stood in the back of the auditorium for the entire three-hour meeting wearing a Revolutionary War-era wool West Jersey Artillery uniform. He asked the developer to consider the possibility that historical artifacts might be on the land.

Toll officials said they are aware of the area's historical significance and had moved the development to the east on the property in response. They also plan to use the farm's stable as part of a recreation facility and the barn as a formal space for residents.

"We're here to listen to suggestions to make this project better," said Andrew Semon, Toll's division president.

Mindy Rhodes, a 43-year-old West Bradford Township resident who said she grew up near the farm and used to ride her horse there, summed up the thrust of the opposition.

"We love this area," she said. "The value here - and you're going to take it away from us."

Toll reached an agreement of sale with the Robinson family, which owns the land, and last month the builder submitted three plans to the township. All three leave more than 190 acres of the land as open space and keep the two existing homes on the property.

Two of the proposed developments include 200 single-family homes and 117 townhouses - 319 total, counting the two existing homes. A third proposal includes 152 single-family homes and 243 townhouses for a total of 397 housing units. This plan would require Toll to provide additional public improvements, such as road improvements and recreation facilities.

More than a decade ago, town officials approved the construction of a retirement community on 60 acres of the land, according to the planning commission, but it was a victim of the Great Recession. A proposal for apartments followed, but the developer withdrew its application after a long period of negotiations with township officials.

The planning commission is scheduled to give its recommendations about the project to the township's Board of Supervisors at the beginning of next year. The board is expected to take up the issue in early February.