WASHINGTON — Though its physical construction is years away, the National Museum of African American History and Culture this week inaugurated an online spot where visitors can help shape its content.

One feature of the Web site is a Memory Book, where people can submit a story, photograph or audio recording that tells something about themselves or a moment in black history.

Other components give a broad look at things the museum is likely to include, such as highlights of the museum's first exhibition, 100 portraits from the National Portrait Gallery and the International Center of Photography, to open at the National Portrait Gallery next month.

The museum has also posted recordings of actor and singer Paul Robeson and activist Angela Davis. The recordings are from the archives of the Smithsonian Folkways Recordings.

Lonnie Bunch, founding director of the museum, said the virtual presence would provide more visibility. After years of political battles, the museum won approval in 2003. It is scheduled to open in 2015 on the Mall.

"This is another tool that helps us hear, learn from and reach the public," Bunch said. "We will always be a place of scholarship, and the presentations will be informed by that."

The site was developed by IBM, using social-networking technology that will allow visitors to contribute content and build their own community.

"This is an opportunity for people to be part of the curatorial process, to contribute their own memories, their own treasures," said Stan Litow, IBM's vice president of corporate affairs. "They are part of the creation of the content and connections."

The memory-sharing, he said, could be about the impact of the Rev. Martin Luther King Jr.'s 1963 "Letter From a Birmingham Jail" or watching Nelson Mandela walk free after 27 years of imprisonment.

Litow said IBM's involvement was initiated by Samuel Palmisano, the company's chairman.

He is a member of the museum's advisory council. IBM's work was equivalent to a $1 million donation, the company said.

The site has built-in systems that will review and edit the materials. "There is a technological monitor that prevents people from writing racist rants and swear words," said Bunch. "Initially, IBM and our staff, and then ultimately our staff, will look at it for accuracy."

Initial contributors to the Memory Book are Willie Brown, former mayor of San Francisco; Michael Lomax, president of the United Negro College Fund; and Kelvin Fowler, who describes how his great-great-grandfather escaped slavery by joining a group of fishermen.

Part of the Web site is devoted to instructions about identifying and preserving photographs, diaries and legal documents. Bunch also is scouting for collections that could be donated to the museum.

"I'm convinced that most of the 19th and 20th century is in people's homes, in the attic and basement," Bunch said.