The historic 16-acre estate of Frederick Douglass, a former slave who became an eloquent abolitionist, publisher and U.S. ambassador, yesterday joined the Lincoln Memorial and Washington Monument as one of the main attractions on official Washington tours authorized by the Department of the Interior's National Park Service.

Interior Department officials said the estate is the first landmark dedicated to the achievements of a black American to be included in official tours here.

The Park Service yesterday sponsored an inaugural 2 1/2-hour Washington tour that was highlighted by a ceremony on the front yard of the Douglass estate, called Cedar Hill. The estate, at 14th and W streets SE, includes a palatial white house with a panoramic view of downtown Washington and the outlying skyline. The federal government acquired and restored the house in 1962.

About 300 spectators and a half-dozen government officials attended the event, including a special assistant to President Reagan, D.C. Del. Walter Fauntroy and District Mayor Marion Barry.

The Ketcham Elementary School Choir sang several songs at the ceremony, and Dexter Nutall, a student at Annunciation School, sang "The Battle Hymn of the Republic."

Melvin Bradley, an aide to President Reagan, congratulated officials responsible for adding the home to the tour route of Landmark Services, Tourmobile Inc., which operates sightseeing tours for the Park Service. "On behalf of President and Mrs. Reagan, I congratulate you. . . . Frederick Douglass was a black man but, beyond that, he was a true American."

City Council member Nadine Winter (D-Ward 6) said that the Douglass tour would help bring more attention to Anacostia and could help foster economic development in the area.

Frederick Douglass was born in 1817 on Maryland's Eastern Shore. As a slave, he learned to read and write and acquired an uncompromising desire to be free.

He became a staunch abolitionist protesting slavery here and started his own newspaper, called The North Star. After the Civil War, he was recognized as the leading spokesman for the newly freed blacks.

He went on to become an adviser to four presidents and served as a U.S. marshal, as the first D.C. recorder of deeds and as minister to Haiti. He died in 1895.

The Frederick Douglass home will be a part of a tour conducted on a 19-passenger van that will pick up passengers at Arlington Cemetery, the Lincoln Memorial and the Washington Monument, said Tom Mack, president of Landmark Tours. The tour will visit several sites in addition to the Douglass home.