A new era is rapping at the door to Gum Springs, a black enclave rich in history in the midst of growing Fairfax County. But yesterday, residents facing the future with a mixture of pride and uncertainty gathered to celebrate the spirit of this community, which was settled by descendants of former slaves.

Among the several hundred who assembled for an energetic parade and a host of speeches was Judy Burton. Her ancestor, West Ford, one of George Washington's former slaves, bought the land, which now is home for about 2,000 residents off Richmond Highway, two miles north of Mount Vernon.

Like many others, Burton is troubled that the legacy of her great-great-great-grandfather is being threatened by the high rises and increased rents that have arrived with Fairfax County's development boom.

"We need housing, we don't need more office buildings," said Burton, a reading specialist at Fairfax's Fort Hunt Elementary School who wrote her doctoral dissertation at Vanderbilt University on Gum Springs history.

Gum Springs residents have staved off a number of development proposals, and in 1979 succeeded in getting the county to designate their community a conservation area. That removed much of the threat of commercial development that did not have the approval of community residents.

Even so, residents are unsettled. They say they worry about development and gentrification, as well as about newcomers who are unaware of the fabric that binds their community.

"We're concerned about Gum Springs itself and whether the community will allow itself to drift into oblivion," said Ronald Chase, a graphic designer who is president of the Gum Springs Historical Society.

Gladys Quander Tancil, 66, who is a descendant of a slave and is involved in Gum Springs affairs, shares that fear. "We as a black community are being swallowed everywhere," said the Groveton resident. "We are being displaced. Our land is being sold to developers. And pretty soon we just won't exist."

Residents and visitors assembled early yesterday for a day of solidarity and community pride.

It began with a parade of residents, politicians, high-stepping horses and chanting children holding hands, balloons and banners. The parade stopped traffic on Richmond Highway and weaved its way to the Martin Luther King Jr. Memorial Park, where the all-day celebration was held.

The Saunders B. Moon Community Action Association, a 22-year-old antipoverty agency that provides a variety of government-funded educational and social activities to residents living in the area, sponsored the event.

"Our purpose is to maintain Gum Springs as an affordable enclave within the more affluent society known as Fairfax County," said the center's executive director, Charlotte Branch.

But that has not been an easy task. During the last 10 years, the center's independence and reputation were tarnished by financial problems and frequent staff turnovers. The center was placed under county trusteeship in 1979, when it was more than $100,000 in debt.

That may change, however. John F. Herrity, chairman of the Fairfax County Board of Supervisors, drew a round of hearty applause yesterday when he told the crowd that the county was considering ending the trusteeship. He said he intended to discuss the matter with the county executive, J. Hamilton Lambert, tomorrow.

Over the last year, the center has made significant strides, Herrity said in an interview. "It's called leadership," he said.

As in other parts of the county, affordable housing for people with low and moderate incomes has long been a problem in Gum Springs. But over the years, the community has been able to improve the situation somewhat with government-subsizided housing.

Still, some express disappointment at the most recent housing development, the 105-unit West Ford town house project. Because the town houses are cooperatives, residents said they could not buy them.

"People want to own their housing," explained Sadie Lyons, who works with the Saunders B. Moon center. "At one time, this was their land, and they are anxious to call it theirs again."