The paper napkin is clipped to Dorothy Porter's shirt. She's eating an early dinner of chicken, carrots and peas. "Go on and talk," she says, pushing her plate away, "I want to get rid of you. Seems like every time I try to do something these days, there's somebody asking me a bunch of questions."

At 91, Porter has a lot of memories worth unearthing. Even though her short-term recall is slipping a little, her distant recollection is remarkable.

As a librarian and curator of the Moorland-Spingarn Research Center at Howard University for nearly half a century, she compiled numerous bibliographies and compendiums of African American history. Her 1971 book "Early Negro Writing" has just been reprinted by Black Classic Press in Baltimore and she's putting the finishing touches on a study of the Remonds of Salem, Mass., a family of black abolitionists. But her masterpiece, the work she will remember most and the work for which she will most be remembered, is the labor that transformed the research center into one of the largest collections of African American history in the country.

Her memories, like her volumes, are sorted, catalogued and shelved.

"My mother wanted me to be a teacher," Porter recalls. Her soft, smiling face goes sour. "I didn't want to teach. I never became a teacher but all these years I've been teaching. You do it incidentally."

After graduating from Miner Teachers College in Washington in 1925, she received a bachelor of arts degree from Howard in 1928 and took a job in the university's Carnegie Library.

In the late afternoons she walked from work to her home near campus with a neighbor, her boss, E.C. Williams. He spoke of the classics, of music and of scholarship, she says, and he was concerned about cultural memory loss.

In 1930 he asked her to assemble for the library a collection of books by black Americans. Williams's simple request became the focal point of Porter's lifelong work: the gathering and organizing of black American history.

"When I started building the collection," she says, "nobody was writing about blacks in history. You couldn't find any books."

There were about 3,000 books by black authors in the Howard library, many given to the school by Jesse E. Moorland, general secretary of the YMCA, in 1914. Using those volumes as the core, Porter began amassing books, papers, pamphlets, sermons, documents, anything written by black Americans. Eventually the collection contained more than 180,000 articles. She was a woman possessed.

She haunted estate sales, library discard piles and used-book stores. "I would go out and beg for books," she says. "I would sweep up their basements."

In the course of her quest, she discovered a multitude of chronicles by prominent and not-so-prominent African Americans. Among them:

A letter from Benjamin Banneker to Secretary of State Thomas Jefferson in 1791. Banneker, a surveyor who helped lay out the District of Columbia, encouraged Jefferson to consider black people equals.

A stinging indictment of slavery by public speaker Maria W. Stewart. She was quoted as saying in 1832: "And, my brethren, have you made a powerful effort? Have you prayed the legislature for mercy's sake to grant you all the rights and privileges of free citizens, that your daughters may rise to that degree of respectability which true merit deserves and your sons above the servile situations which most of them fill?"

The brief autobiography of Jarena Lee, who in 1836 became the first black woman to petition the African Methodist Episcopal Church for ordination.

Without the labor of Dorothy Porter, the writings of these folks and countless others might have turned to dust. Scholars have swarmed around the collection.

Porter says historian Louis Harlan used the center to research his books about Booker T. Washington, and William McFeely called on Porter's legwork for his biography of Frederick Douglass.

David Levering Lewis, biographer of W.E.B. Du Bois and Martin Luther King Jr., says he cannot imagine anyone who has written about African American history who has not benefited from Porter's work. The Moorland-Spingarn collection, he says, has been indispensable to his research and "it's unimaginable that it would have achieved that kind of capacity without Dorothy Porter's early stewardship."

Books have been her salvation, says Porter. But she's been so busy collecting other people's books, she hasn't been able to read as much as she would have liked.

"I read through osmosis," she explains, sitting in her dining room. She is surrounded by stacks and stacks of books, piles and piles of paper and the fantastic paintings of Africa by her first husband, James Amos Porter, who was chairman of the Howard art department. He died in 1970.

Porter retired in 1973, then married Charles Harris Wesley, a historian. He died in 1987. For a while she wrote under the name Dorothy Porter Wesley.

She was the first black woman to receive a master of science degree from Columbia University. In 1962, the Ford Foundation sent her to Nigeria to build a national library.

Porter calls to her daughter, Constance, who has taken her mother's plate into the kitchen: "Coni. Am I going to have dinner tonight?" Constance Uzelac, her only child, is upstairs. She has helped her mother write her many books over the years.

Porter has lived in the two-story brick house near Gallaudet University's Northwest Washington campus since 1969. "I was the first colored person to move into this neighborhood," she recalls.

When she arrived, she expected people to be cold and aloof, but she says she felt welcomed from the beginning. "Neighbors brought dishes for me," she recalls. "It's a good neighborhood."

In one breath she says if she can just finish the book on the Remonds, "I can go to Heaven happy, or wherever I'm supposed to go."

In the next breath she says she's got another book in mind, one about William Cooper Nell. He was this country's first black historian, she explains, and he gave prominence to such African American patriots as Crispus Attucks, "who started the American Revolution."

And she's helping the folks at her church, St. Luke's Episcopal, write a history of the parish. "Alexander Crummell was the first pastor," she says. "He gave the first sermon."

She grins. "The only rewarding thing for me is to bring to light information that no one knows. What's the point of rehashing the same old thing?"

Porter doesn't get out as much as she used to. She'll occasionally attend a special reading at Vertigo Books. Last fall she went to the White House to receive the Frankel Award from the National Endowment for the Humanities. Recently she signed copies of her book at Howard, but did not visit the new museum room that is named after her. She's given up on going to church, however. She has arthritis in her feet and it hurts to walk. Her house is equipped with a lift on the stairs, but more and more she needs assistance.

She's concerned because for the first time in her life she's not feeling well. "I've never been sick a day in my life, never been to the doctor," she says.

Uzelac is trying to help her mother get organized. Looking around, a visitor can see she has her work cut out for her. Dorothy Porter, once described by James Billington, the librarian of Congress, as a "librarian extraordinaire," is a bit overwhelmed by her material.

Uzelac would like to take her mother to Florida, but Porter is reticent. She waves a hand in the air. "I've got all this work here to do," she says. CAPTION: Dorothy Porter (in a 1992 photo): "When I started building the collection, nobody was writing about blacks in history." CAPTION: Dorothy Porter has built one of the country's largest collections of black American history.