A YOUNG BLACK MAN once asked an old black man what could be done to preserve and enhance the rights of black people. The old man, an internationally known orator, had just one word of advice: "Agitate."

The old man was Frederick Douglass, an escaped slave from Maryland's Eastern Shore who had become an eloquent spokesman for the abolition of slavery. The young man was a Howard University student named Martin Andrew. (He later asked the same question of another former slave, Booker T. Washington, who advised, "Work.")

In 1877, when Douglass was about 60 (like many slaves, he never learned his exact date of birth), he bought a Victorian house in Anacostia, was able to get around a whites-only restriction on the deed. Now open to the public, the 14-acre estate, called Cedar Hill, overlooks the Anacostia River and a virtually all-black neighborhood of row houses.

Douglass was an agitator even as a young slave. He taught himself to read, a crime punishable by death. Later he taught other slaves to read, an equally subversive act. Just as his owner had feared, reading introduced him to texts that decried the injustice of slavery and fueled his burning desire to be free.

Douglass had no parental guidance. His mother had been sold to another farm when he was an infant, and he never knew for sure who his father was. Friends told him that his father was his white master, a man Douglass described as "a cruel man, hardened by a long life of slave-holding." Remarkably, Douglass felt compassion for slaveowners who fathered children by slaves.

"The master is frequently compelled to sell {his mulatto children} out of deference to the feelings of his white wife," he wrote in Narrative of the Life of Frederick Douglass, "and, cruel as the deed may strike anyone to be, for a man to sell his own children to human flesh-mongers, it is often the dictate of humanity that he must do so; for, unless he does this, he must not only whip them himself, but must stand by and see one white son tie up his brother . . . and ply the gory lash to his naked back; and if {the father} lisp one word of disapproval, it is set down to his parental partiality, and only makes a bad matter worse, both for himself and the slave whom he would protect and defend."

When Douglass was about 16, his master sent him to a professional slave breaker. After six months of weekly whippings and exhausting work, Douglass fought back one day, bloodying the surprised slave breaker in a fistfight that renewed Douglass' pride. The teen-ager then resolved never to be hit without hitting back, and over the next four years he had fights, but was never whipped.

In 1838, about age 20, he escaped to New York. There he endured hunger, loneliness and the constant fear of bounty hunters. But Douglass' sense of justice led him to a meeting of abolitionists, where he made a short speech. So impressed were the abolitionists with his poise and eloquence that they hired him as a traveling lecturer. Ironically, he was too eloquent; some audiences doubted he had ever been a slave.

Douglass' three autobiographical volumes graphically depict slavery and boldly set forth his views. Of Christian hypocrisy, he wrote: "The religion of the South is a mere covering for the most horrid crimes, a justifier of the most appalling barbarity, a sanctifier of the most hateful frauds, and a dark shelter under which the darkest, foulest, grossest, and most infernal deeds of slaveholders find the strongest protection."

Yet he blamed the institution of slavery, not its practitioners, for its horrors. Of one mistress, he wrote: "Slavery proved as injurious to her as it did to me. Under its influence, {her} tender heart became stone, and {her} lamblike disposition gave way to one of tiger-like fierceness."

Douglass published his own newspaper, recruited black Union soldiers, advised President Lincoln about the needs of black soldiers, and served as U.S. Marshal for the District of Columbia. After the Emancipation Proclamation, he agitated for the vote for black men ("Without the vote, liberty is a mockery") and later worked with Susan B. Anthony and Elizabeth Cady Stanton to secure women's suffrage.

He was a friend of Harriet Tubman (who jokingly described herself as "just an old lady that likes to do a lot of walking in the great outdoors") and Harriet Beecher Stowe, who reportedly wrote Uncle Tom's Cabin from a tiny desk now displayed at Cedar Hill. Widowed after 44 years of marriage to Anna Murray, a free black woman with whom he had five children, Douglass eventually married his secretary, Helen Pitts, a white abolitionist. Douglass' children were mortified, but he argued that if he didn't marry Helen "just because she happens to be white," he would be a "moral coward." He died at Cedar Hill in 1895.

"Agitate" has many meanings, including this one: "To stir up public discussion of." The Cedar Hill house, the film shown there, and the books available in the small shop all act as springboards for public discussions of slavery, courage, interracial marriage, atrocities in the name of religion, and other issues that deserve to be continually examined anew.

National Park Service rangers from the Frederick Douglass National Historic Site and other volunteers will present "Slaves to Soldiers," a historic reenactment of black men's participation in the Civil War, Saturday at Harpers Ferry and on November 12 at Fort Dupont Park. Both presentations are from 6:30 to 8:30 p.m. and are free. Call 426-5961 for more information.

THE FREDERICK DOUGLASS NATIONAL HISTORIC SITE, 1411 W Street SE, is open daily from 9 to 5. A film (with captions for the hearing-impaired) is shown on the hour, and guided tours of the house are offered afterward. Limited wheelchair access; 426-5961.