A few years ago, Rex Ellis, the associate director of curatorial affairs for the National Museum of African American History and Culture, which will open in September on the Mall in Washington, D.C., made a phone call. Ellis is a natural storyteller, with a voice that mixes congestion and control in a manner reminiscent of Jesse Jackson’s. He’d clearly told the story of the call before, but when I spoke with him this past spring, in his office on an upper floor of the glassy Capital Gallery Building, on Maryland Avenue, he repeated it for me with all the shock and wonder that it warranted.

“A phone call,” he began. “To a young lady by the name of Wendy Porter.” She had e-mailed him, saying that she had Nat Turner’s Bible. Ellis smirked slightly and rolled his eyes. “Well, there are a lot of folk who call and make all kinds of claims. So I said, ‘Mmm-hmm.’ But then she told a little bit about her history, and she mentioned Nathaniel Francis. And I said”—deeper this time, slower—“ ‘Mmm-hmmmm.’ ”

Nathaniel Francis owned the property on which Nat Turner was captured, in October, 1831. There, on Francis’s land, the slave preacher hid, having led a revolt of fellow-slaves that drew its inspiration from the Bible in question and ended in the deaths of at least fifty-five white residents of Southampton County, Virginia. Turner was tried and hanged in the nearby town of Jerusalem. It is not clear to Ellis or to his staff just how Francis came to have Turner’s Bible; later, by searching through library documents and photographs, they learned that his family had held on to it until at least 1900. As if to complete the circle of haunted serendipity, Wendy Porter’s stepfather was related to one of Nathaniel’s descendants, Rick Francis, a prominent member of the Southampton County Historical Society, which owns the sword that Nat Turner had with him when he was captured.

“So,” Ellis said, tracing ecstatic connections on his desk with his fingers, “everything just started to fit together.” He travelled to Virginia Beach to see the Bible. Porter, who was seven or eight months pregnant, greeted him at the door of her home and introduced him to her mother, who took him to the dining room. Porter’s mother went into a closet and pulled down an object wrapped in a thinning dishtowel. She placed it on a table in front of Ellis. Sitting in Washington, Ellis pantomimed the gesture, sliding an invisible book across his desk, to me.

When Ellis unwrapped the Bible at the Porters’, the binding was long gone. What he saw was its first yellowed page, the edges rounded by much use. He turned a few pages, gingerly, then stopped. He looked at the mother. “We only bring it out during family reunions,” she said. “And only when someone asks do we bring it out so that they can see it. Then we wrap it up and put it back in the closet.”

She looked at the Bible. “We thought that this was something—we knew it was important,” she said. “Yes, Ma’am,” Ellis replied. Then she spoke again, as if urged, Ellis said, by some outside force. “It was time for it to leave here,” she told him. Ellis looked me in the eyes when he repeated what she said next: “Because there’s so much blood on it.”

In the introduction to “America’s Black Past,” an anthology published in 1970, the historian Eric Foner wrote that, among this country’s “myths and misconceptions, one of the most pervasive and pernicious . . . is the picture of blacks as inactive agents in history.” An active history, like the one that lay behind Nat Turner’s bloody Bible—full of inscrutable decisions and odd happenings, shaped but not determined by suffering—often stays hidden. The Bible will soon go on display at the new museum on the Mall, our latest opportunity to bring such a history into the light.

The museum’s mouthful of a name—and its inelegant initialism, N.M.A.A.H.C.—testifies to a bureaucratic slog that began in 1915, when black veterans of the Union Army, together in Washington to celebrate the fiftieth anniversary of the war’s end, and fed up with the discrimination they found in the capital city, organized a “colored citizens’ committee” to build a monument to the civic contributions of their recently emancipated people. In 1929, Herbert Hoover appointed a commission, which included the civil-rights leader and educator Mary McLeod Bethune and the N.A.A.C.P. co-founder Mary Church Terrell, to come up with a plan. Unfunded and largely ignored, the commission languished, and was eventually dissolved by Franklin D. Roosevelt. The effort began again in the nineteen-seventies, with several abortive attempts at legislation and much controversy within the Smithsonian Institution, under whose aegis each national museum is administered. Finally, in 2003, George W. Bush signed the National Museum of African American History and Culture Act, which had been sponsored in the Senate by Sam Brownback and in the House by John Lewis, the project’s most consistent contemporary champion.

In 2005, Lonnie Bunch was hired to be the museum’s founding director. Bunch, now sixty-three, previously served as the associate director for curatorial affairs at the National Museum of American History, and then spent five years as the president of the Chicago Historical Society. We spoke this past April, on a muggy day in Washington, in his office at the Capital Gallery Building. He told me the story of how, after being hired by the N.M.A.A.H.C., which had “no collection, no money, no staff, no site,” he was greeted at an earlier set of offices, at L’Enfant Plaza.

“I go over there—door’s locked,” he said. “So I go to security and say to the guard, you know, ‘I’m the director of this new museum.’ He says, ‘We don’t know who you are—you can’t get in.’ So I go to the manager’s office: he won’t let me in. I call back to the Smithsonian and say, ‘What’s going on here?’ They say, ‘We don’t know.’ So I’m standing in front of the door, really ticked off, thinking, Why’d I take this job? But then this maintenance guy walks by, and in his cart he’s got a crowbar. So I take the crowbar and break into the offices.”

I may have looked skeptical. “Nobody was ready for us,” he insisted. “I had to break in.”

The difficulty of the past decade’s work is a theme with Bunch—he says he plans to publish a book about the experience, called “A Fool’s Errand”—and this story was perhaps offered as an allegory, both for the tortuous process of opening a national museum and for the history of black people in America. Or, at least, one version of that history: first a promise; then a series of closed doors; then despair; then, at last, access by way of force instead of grace. “I’m a kid born in Newark,” Bunch said, arching an eyebrow, “so I know how to fight.”

That pugilist’s impulse, along with an intimate understanding of the politics and the pace of the Smithsonian, has, from the beginning, informed Bunch’s approach to the technical and diplomatic aspects of his directorship. When he was deciding whether to leave his job in Chicago, he spoke with Richard M. Daley, the city’s former mayor. Daley, characteristically blunt, asked, “Why would you leave to run a project?” The question stayed with Bunch, and led him to conclude that, even without a physical space of its own, the museum must exist, not aspirationally but in fact, starting soon after his appointment.