She searched the shelves of the airy, wood-beamed store near the MacArthur BART station in vain and finally asked Cherysse Calhoun behind the counter for help. All the store had was a calendar featuring pictures of blues legends.

Lewis wasn't inspired, but that didn't send her to the giant chain bookstores a few miles down 40th Street to Emeryville. Lewis said she would check back in a few weeks instead.

"I believe we have to support our black businesses," Lewis said as she lingered near portraits of African-American legends such as civil rights leader Malcolm X and writer Zora Neale Hurston. "Marcus has been such a service to the community for years. We've got to do what we can to keep them alive."

Since opening its doors on Fillmore Street in San Francisco 45 years ago and on Oakland's Martin Luther King Jr. Way in 1976, Marcus Books has done more than sell books by and about African-Americans.

Named for black leader Marcus Garvey, the stores have shown deep affection and concern for the community they serve and, in the process, won the loyalties of customers and writers from across the country.

Luminaries such as writer Toni Morrison and boxing legend Muhammad Ali are friends of the owners and have drawn huge crowds to events at the Oakland store. Hundreds attended a memorial service for owner Julian Richardson when he died at age 84 in 2000.

Perhaps the oldest operating black bookseller in the nation, Marcus Books has been a place where countless African-Americans learned about themselves through the printed word, said Richardson's widow, Raye.

"I think it's been central to Bay Area black culture," the 84-year-old San Francisco resident said. "It has brought well-known and aspiring writers to an audience that was receptive and needed what those authors brought."

In the 1950s, mainstream bookstores carried few if any titles by black writers, and few publishers printed them, Richardson said. That shortage inspired the Richardsons to open a printing business and publish works by black writers.

"We had to cull titles from everywhere to get even a small list," she said. "The first publishers worked from the perspective that blacks didn't read. Yet our community was hungry for literature."

Black readers devoured black history books such as "Stolen Legacy" by George G.M. James, which the Richardsons published, as well as works by writers such as Richard Wright and Langston Hughes. The last book is still one of the stores' most popular titles, said Calhoun, 35, who is Richardson's granddaughter and has worked at Marcus Books all her adult life.

"That store made us all a little more aware of our history," said Oakland-based writer Guy Johnson, whose mother, poet Maya Angelou, is a longtime friend of Marcus Books. "We need to know the names of the people who stood up and sacrificed themselves for us."

At the peak of the civil rights and black power movements, the San Francisco store, which has moved seven times, served as a nerve center.

Malcolm X visited and consulted with Julian Richardson about the issues of the day. The stores' press, which still acts as a commercial printer, produced pamphlets for the Black Panthers. Other friends have included baseball legend Jackie Robinson, intellectual Cornel West and East Bay-based writer Alice Walker.

"Anybody who was doing positive things for black people sought (Richardson's) counsel," said his daughter Karen Johnson, who runs the San Francisco store. "The store is like a clean mirror where you can get a true picture of yourself. It teaches the value of blacks, things that are untaught in public schools."

Today, the stores are fighting the same battle as many other independent bookstores: They are trying to survive an economic landscape increasingly dominated by chains.

Johnson said the family has stayed in business by placing social good above profit. Nonetheless, it closed one Oakland store last year, she said.

Andy Ross, owner of the much larger Cody's Books stores in Berkeley, said Marcus Books represents a concept that is struggling to survive.

"They are in their communities, they are so involved and they are about ideas," he said. "They are real heroes to independent booksellers."

To Johnie Wright, who has run first an auto body shop and then a fruit stand across the street from the Oakland site since 1958, Marcus Books is above all a good neighbor.

From April to October, when Wright's fruit stand is in business, customers who spend more than $50 at the bookstore are treated to a free watermelon from Wright.

"They've been wonderful neighbors," the 80-year-old man said. "They have books no one else has. I've bought many books from them over the years."