Beyond land and money, the new museum needed things to show and a building to show them in. No Smithsonian museum had ever started life without a collection. The museum’s team collected artifacts from around the nation in an “Antiques Roadshow”-style program in 15 cities called “Save Our African American Treasures.” The program yielded many of the 40,000 objects the museum now holds — 3,500 will be exhibited when the building opens — and elevated the museum’s profile.

For the design of their new home, museum officials created a selection committee and displayed the final six plans at the Smithsonian Castle in an effort to be transparent about the process.

The winning design, by a team led by the Tanzanian-born British architect David Adjaye, spoke of “uplift, resiliency and spirituality,” Mr. Bunch said, and the bronze color gave the building the symbolism he sought.

“I love the notion of a darker building,” he said, adding: “There’s always been a dark presence in America. There have always been African-Americans in this country shaping it whose story gets overlooked or undervalued.”

It was also a vast departure from some of the design proposals he had been sent within days of his appointment as director in 2005. One envisioned a building shaped like a black-power fist, hardly appropriate for the museum he foresaw or that Congress had agreed to finance. He quickly moved on to other options.

“I knew what I didn’t want,” he said.