In 2009, the family of Emmett Till, the 14-year-old boy killed in Mississippi in 1955, gave the museum his original coffin. (In 2005 Till's body was exhumed for a federal investigation into the crime, and the body was reburied in a new casket.) The photographs of the slain boy lying in an open casket in publications like Jet magazine became a pivotal rallying cry for the modern civil rights movement. Also on the museum's wish list is an airplane flown by the Tuskegee Airmen, the famed black fliers of World War II.

The collection has been built through "Save Our African American Treasures" sponsoring workshops around the country, where the public brings articles to be inspected, donations of collections and the spontaneous "over the transom" inquiry. Additional unexpected exposure happened recently when Bunch received a BET Honor, the first to be given to a person from the museum world. And a cache of 700 garments and 300 accessories from the defunct Black Fashion Museum was donated by Joyce Bailey, the daughter of the museum's founder, Lois Alexander Lane.

The subjects to be emphasized in the National Museum of African American History and Culture continue to evolve, Bunch says, and the materials will be a strong guide. So far, the museum will cover slavery, segregation, the civil rights movement, and sports and entertainment; it will also establish a Center for African American Media Arts. "We have about 10,000 artifacts -- and we need 20,000 more," he explains. He wants to tell the rich experience of men and women in the military and is scouring for more materials from the World War II era, as well as the rich records of black clubs.

While the monumental objects are the keys to the visual story, Bunch says that smaller items are also important connections for visitors: an 1850 slave badge from Charleston; a letter signed by Toussaint L'Ouverture; a sign from a Nashville, Tenn., bus that reads, "This part of the bus for colored race"; and a Selmer trumpet once owned by Louis Armstrong.

Recently the museum acquired a collection of rare photographs of the great writer James Baldwin. These photos were taken in casual moments in Turkey by photojournalist Sedat Pakay. Lena Horne's family recently donated a gown that the groundbreaking singer and actress wore. Bunch has also collected a costume and turntable from hip-hop pioneers Public Enemy, plus a bleacher seat from Atlanta's Perry Stadium, where the Negro League baseball teams played.

"A woman in Birmingham had lived in the city at the time of the bombing of the 16th Street Baptist Church. She picked up glass shards from the church windows and saved them," says Bunch, confident that the tiny glass remnants will have the same emotional impact that they had on him.

The museum's interior, covering 82,000 square feet, will be designed by a diverse team from Ralph Appelbaum Associates, the internationally known exhibition firm that put together the moving galleries inside the U.S. Holocaust Memorial Museum. 

To keep reminders of the museum's progress in front of its potential audience, and to test the curatorial ideas, the museum has mounted exhibitions in Washington and around the country. The traveling multimedia exhibition "Ain't Nothing Like the Real Thing," a history of the famed Apollo Theater, is now in New York City and is scheduled to visit Atlanta. "These shows give me a model to show the public and give the staff a way to show off their expertise," says Bunch.

It's all a foreshadowing of the stories that all Americans will walk through in a few years, and another step in Bunch's journey to make certain that the African-American perspective is part of everyone's story.

Jacqueline Trescott covers arts institutions for the Washington Post.

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