Just before sunrise at the Smithsonian Institute's National Museum of African American History and Culture. (Jahi Chikwendiu/The Washington Post)

The hole in the ground was several stories deep, more than 300 feet wide and at least 500 feet long. Temporary walls had recently gone up around the spot where the long-awaited National Museum of African American History and Culture was going to be built.

The museum’s director, Lonnie Bunch, recalled standing on the edge of that hole one weekend four years ago, looking down at a steady stream of liquid. He pictured water seeping into galleries filled with precious artifacts.

“I thought, ‘Oh, my goodness. What did I do?’ ” he said.

Bunch and exhibit designers from Ralph Appelbaum Associates had persuaded Smithsonian officials to dig an additional 45 feet to create a more dramatic exhibit space. Instead of having the history galleries on one level, there would be three tiers of exhibits within a larger space where the ceiling reached more than 50 feet high. From his time working at the National Air and Space Museum, Bunch knew people “really loved those moments to get intimate with large objects.” He and the other curators had already found a Jim Crow-era Pullman rail car and a Tuskegee airplane to display. But now they needed to stop the water coming in.

The museum sits on what was once the south bank of Tiber Creek, which was filled in late in the 19th century.

Architects and engineers came up with a solution — erecting a kind of giant underground bathtub around the museum to help divert water — but it was just one of many instances that required improvisation, no small feat for a massive team of architects, curators, exhibit designers, engineers and building contractors.

How the National Mall became what it is today

When the first members of the public step on the polished floors and glance at the airplane suspended above, they’ll be oblivious to those brief episodes of panic such as the one Bunch had that day. (“I’d love to tell you there was a weekend when I wasn’t worried,” he said.) Yet such moments shaped what visitors will see for decades to come and, in many cases, Bunch and others said, made the finished product better.

Bunch said that because he had to raise money while the museum was being developed and built, he couldn’t hire exhibit designers right away. When they did start, they drew up three possible layouts. Expanding the gallery space was the most audacious, said Melanie Ide, project director for Ralph Appelbaum Associates, “because it had all kinds of repercussions in terms of complexity and cost.” But everyone agreed the result would be worth it. “We had only one shot to do it right,” Bunch said. “It was crucial to be as bold as it could be. It had to be as bold as the outside.”

Bunch was referring to the building’s now- iconic exterior: three tiers of inverted half-pyramids, sheathed in a shimmering bronze-hued screen cut in an abstract pattern based on the intricate ironwork created by freed slaves in New Orleans and Charleston, S.C. An enormous roof over the entrance creates a giant porch. A water feature helps cool the porch on hot days. The idea, said architect David Adjaye, is to provide visitors with “instant comfort.”

At first glance, the location seems logical — between the Washington Monument and the Mall’s museum core. But for the architects — Freelon Group (now part of Perkins and Will), SmithGroupJJR, Davis Brody Bond and Adjaye — it was a headache.

“The site has always had an identity crisis,” said Zena Howard, an architect with Freelon who coordinated the work of the four architecture firms and the Smithsonian. “Some people saw it as part of the formal rhythm and geometry of the Mall, and some people saw it as part of the Washington Monument, which has a rolling landscape.” Government officials had said the museum could not overwhelm the monument or be taller than the neighboring museums and Depression-era office buildings in Federal Triangle.

At the same time, “everyone was always on the same page that the building should be distinct,” Howard said. “Of its own place and own time and not the time of some of its adjacent neighbors.”

Adjaye, the sought-after British architect and son of Ghanaian diplomats known for fusing artisan detail with simple, powerful shapes, said he wanted to provide a “punch” at the end of the “row of palaces,” as he referred to the other museums. And the architecture needed to “speak the story of the museum, the origins in Africa,” he said, and not be another “stone box with things in it.”

An early sketch from the architects of the museum. (National Museum of African American History and Culture)

He came across a wooden sculpture of a man wearing a crown by the early-20th-century Yoruban artist Olowe of Ise. Adjaye had seen similar forms in Benin, in fragments of doors and posts and pillars. But the connection to the Yoruba, one of the largest ethnic groups in Nigeria, was more meaningful. A 2015 Oxford University study found the majority of African Americans and modern-day Yoruba people in West Africa have a similar ancestry, confirming that the region was a major source of African slaves . He sent an image of the sculpture to his collaborators. No other ideas were considered. “I think all of us were captured by it,” said Hal Davis of SmithGroupJJR. In focus groups run by Smithsonian officials later, people associated the shape with raised arms and a sense of uplift that echoed Bunch’s vision for the museum.

Adjaye embedded history into the bronze-colored screen as well. He said it spoke to the centuries of labor free and enslaved African Americans have contributed to building the United States. That visual hat tip to history also aligned with a requirement to make the museum environmentally sustainable. Screens are often used in green buildings to reduce heat from sunlight, while letting in light. Adjaye had wanted the screen to be made of bronze, but the material proved to be too heavy and changes color in the elements. Smithsonian officials went instead with coated aluminum. Perfecting the color took more than a year. But everyone, including officials on the U.S. Commission on Fine Arts, agreed on the importance of getting it right. Bunch said the color not only makes the building distinctive, but is also a reminder of “a strong, dark presence not recognized in American history.”

Inside, there were more compromises. On the ground floor, Adjaye had envisioned a “shower of timber” — vertical wooden beams coming down from the ceiling — “to make you feel the weight of an enormous body of history.” But, Davis said, Smithsonian officials were worried the wood might warp and be hard to maintain.

Other elements from the original design, however, were untouched, including the oculus and the Contemplative Court at the top of the history galleries. The oculus is a round structure that emerges from the ground on the north side of the museum. Inside it is an enormous ring of water showering down to a pool within the Contemplative Court. At night, the oculus glows from within like a beacon, said construction manager Derek Ross. Adjaye said it also refers to pedestals used to auction slaves. The idea came to him after he learned there were once slave pens not far from the museum site.

“This is a profound thing,” he said, “reading the history in the building.”

The architects are eager to see what the public will take away from the finished product. Ide wants visitors to recognize that the museum tells not just “an American story, but the American story.”

On a more personal level, Howard is eager to see her parents’ reaction. Her father, a retired chemist, and her mother, a former schoolteacher, participated in civil rights activities in the ’60s. Howard heard about their struggles her entire life. The idea that there will be visitors hearing such stories for the first time, she said, “blows my mind.” Her role in the project is noteworthy in itself: Black women make up less than 1 percent of licensed architects in the United States.

Ironically, before she can fully appreciate the museum, Howard, who devoted the past eight years to its creation, said she has to stop looking at it like an architect. “When one of our projects ... opens, you have to resist the temptation of obsessing” about the evolution of the design, she said. The public has no idea. “It’s like a phase you go through. It eventually goes away. Seeing this museum full of people engaged in the exhibits will do it.”

Annys Shin is an articles editor for the magazine.

E-mail us at wpmagazine@washpost.com.

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