A small section of Northwest Washington that was an enclave of civility for upper-class Washington blacks during the late 19th century has been designated as the Strivers' Section Historic District and nominated to the National Register of Historic Places.

The formal designation means that the area, roughly bounded by 19th Street on the west, 16th Street on the east, T Street on the south and Florida Avenue on the north, is now protected by the city's historic preservation laws and that property owners in the area can qualify for historic investment tax credits.

The Joint Committee on Landmarks first recommended the district be nominated to the national register in June of 1983, but city officials did not forward the nomination to the national register until last month.

In a December letter to Jerry L. Rogers, associate director for cultural resources for the National Park Service and keeper of the national register, landmarks committee chairman J. Ernest E. Harper complained that the city "appears to continue to be derelict in the execution of its responsbilities under the National Preservation Act."

The Joint Committee on Landmarks served as the city's historic review board until last year, when Mayor Marion Barry established the D.C. Historic Preservation Review Board to take its place.

Because the landmarks committee had been the official historic review body at the time the Strivers' Section was recommended for nomination, however, the committee was legally able to appeal to the national register for help in getting the nomination forwarded.

In recent cases testing D.C. preservation law, courts here have ruled that a historic district becomes effective when accepted for nomination by the national register. Federal preservation laws allow a historic review board to appeal to the keeper of the national register if a nomination has not been forwarded to the national register within 18 months of having been recommended to the state historic preservation officer.

The D.C. state historic preservation officer, Carol B. Thompson, said through a spokesman that the forwarding of the Strivers' Section nomination was delayed because of "technical reviews." Harper, however, said that technical reviews for a proposed historic district as small as the Strivers' Section should not have taken 18 months and that he intrepreted the review as "deliberate delay."

The Strivers' area was first developed in the 1870s by prominent black leaders. Frederick Douglass, the noted 19th-century civil rights leader, is believed to have built three houses on 17th Street in 1875 and owned numbers 2000 and 2004 until he died in 1895, according to documents filed with the landmarks committee. His son, Lewis H. Douglass, lived at 2002 17th St. until 1908.

The area was a prestigious address for black doctors, dentists and educators in the 20th century, and three apartment buildings on T Street were among the first multi-family buildings owned by blacks in the city.

After a 1948 Supreme Court decision striking down racial covenants that had kept blacks and Jews out of most of Washington's nicer sections, the area around U Street declined as many of the black middle-class families moved north up 16th Street. In recent years young professionals, white and black, have moved into the neighborhood, restoring many of the row houses and converting the apartment buildings to condominiums.

In his letter to the keeper of the national register protesting the city's delay in forwarding the nomination, Harper said that a number of investors and property owners had already received approvals from the Department of the Interior for historic investment tax credits that they could not take until the district was officially nominated.

"These investments are jeopardized, and other derelict properties that might benefit from this program decline even further," said Harper. Harper explained that while not all locally designated historic districts are accepted for the national register, the tax credits are extended to approved projects in districts that have been officially nominated.

In addition to nominating the Strivers' Section, Thompson's office also forwarded to the national register the nomination for several blocks to be added to the already-established Dupont Circle Historic District. These include the 1300 block of 22nd Street NW, the 2100 blocks of O and N streets and Newport Place, the 1600 blocks of R and S streets and Riggs Place and 1631 through 1741 17th St.

"We are extremely pleased, no, delighted that they have finally gone forward," said Charles Robertson, president of the Dupont Circle Conservancy, the group that originally made the application to the landmarks committee for the Strivers' Section historic district and the expansion of the Dupont Circle district in 1980. "We kept getting promises and promises from the city that it would go forward but it never did. We are glad that the appeal to the national register worked."