The Smithsonian Institution's impending sale of the Capitol Hill buildings housing the National Museum of African History has upset numerous residents in the neighborhood who fear that their community will be severely damaged if the site is purchased for use as offices by a commercial developer or a foreign government.

The museum will move in August from the property, situated two blocks east of the Supreme Court at 316 A St. NE, to its new home on the Mall at Ninth Street and Independence Avenue SW. The selling price for the property, which includes nine town houses totaling about 30,000 square feet, is $1.9 million.

Several neighborhood organizations recently began trying to persuade Smithsonian officials to sell the property only to a buyer who would return the 100-year-old historic structures back to their original use as residences. Included in the sale package are two buildings once owned by abolitionist and civil rights leader Frederick Douglass.

"We all have problems with who's going to buy it," said Lawrence Monaco, president of the Capitol Hill Restoration Society, a 1,000-member civic group founded in 1955. "The only thing we can do is ask the Smithsonian . . . to give priority to residential developers."

John Clarke, the Smithsonian's assistant treasurer, said, "We are sensitive to the neighborhood's concerns , but we have to be guided by . . . the Smithsonian's interests to sell it to whoever puts forth the best offer."

Clarke said that, although "the neighborhood's preference is to revert the buildings to residences," such a move would be "a fairly expensive prospect."

The Smithsonian hopes to sell all nine buildings as a package, but "we will consider all offers," Clarke said. Bidding closes June 30.

Clarke said he has not received bids, but that at least four parties have said they will submit offers. He refused to identify them, but said they included a residential developer, a nonprofit group interested in using the buildings for offices and a retail developer.

The museum is expected to close later this month to prepare for moving in August, Clarke said.

Neighborhood leaders are especially concerned that a nonprofit group or a foreign government could place an office or chancery at the site because the buildings have not been used as residences for a number of years, despite zoning only for low-density residential use. In a number of cases in recent years, the city has permitted nonprofit groups to place offices in residential neighborhoods.

"We can't stop the sale," Monaco said, but he vowed that his group would contest before a District zoning panel any future buyer's plans The selling price for the property, which includes nine town houses totaling about 30,000 square feet, is $1.9 million. to develop anything other than private residences. Because it is owned by the fedral government, the museum's site is unzoned. It would heve to be zoned before anything could be done to the property.

The Smithsonian's Clarke said that, if the buyer of the property needs a zoning change, "I'd expct we'd try to help."

The museum -- which was a private facility before joining the Smithsonian in 1979 -- bought its first town house on the block in 1964. Since then, about one-half of the north side of the block has been purchased by the museum, according to Jean Salan, the museum's assistant director.

Area homeowners said additional offices will further erode the residential character of their neighborhood and increase traffic congestion in a section of the city where historic preservation has become a leading goal. The museum's current site, Victorian town houses built in the mid-to-late 1800s on an attractive tree-lined street, is part of the Capitol Hill Historic District, which is listed on the National Register of Historic Places. Douglass lived at 316 A St. from 1873 to 1877 before moving to Anacostia.

Some residents, including Monaco, said they are concerned that the buildings could be gutted and then expanded by a developer seeking to gain more office or residential space out of the property, a move that is generally hard to win approval for in an historic district.

But the Smithsonian's Clarke said, "If we get a hint of that's what a buyer is going to do, they won't be a succesful bidder."

Dick Wolf is a member of a citizens planning committee appointed by Mayor Marion Barry that recently submitted a series of proposals as part of the District's current ward planning process. Wolf said his group has recommended that the museum site revert to residential use.

"We don't find museums compatible in a residential neighborhood, either," Monaco said. "But that particular museum was so unique that a number of people were willing to put up with it."