US architecture studios Pei Cobb Freed & Partners and Moody Nolan have unveiled a  museum in South Carolina that is lifted off the ground above a site where many enslaved people disembarked

Designed by Pei Cobb Freed & Partners and Moody Nolan, the International African American Museum (IAAM) occupies a single-storey structure, which was lifted 13 feet off the ground on 18 columns.

The space underneath the structure was left completely open between the columns, except for the massing of the skylit staircase that rises up through the centre of it.

It occupies a site on the waterfront in Charleston, where many enslaved Africans first reached the United States before being sold into forced labour throughout the country.

The IAAM was designed to respect the site by offering programming and exhibitions reflecting on the history of slaves in the United States and to "celebrate the contributions of their descendants".

"The International African American Museum is more than a mark of architecture, it's an extraordinary milestone," said Curt Moody, principal at Ohio-based studio Moody Nolan, which served as the executive architect on the project.

"Having worked for the last fifteen years to dream this into being, we are intimately aware of the cultural significance it has for American history," he continued. "Without this building, this sacred site would have remained unknown and the stories of our ancestors untold."

By raising the structure, the studios were able to respect the site and give the structure visual interest. The material choices on the exterior further reference the history of the site.

The columns were clad in oyster-shell tabby. The ends of the building, which face the water and the city respectively, feature a series of windows framed by angled louvres clad in African sapele.

Much of the remainder of the building was clad with pale yellow brick.

Late architect and co-founder of Pei Cobb Freed & Partners Henry N Cobb played a significant role in the design before his passing.

"As the place where thousands of Africans from diverse cultures first set foot in North America, Gadsden's Wharf is not just the right place to tell this story; it is hallowed ground," Cobb said when the project was commissioned in 2008.

"The special design challenge of the museum is to build on this site without occupying it."

The main entryway is a wide set of stone stairs leading up to a central atrium that is lit from above by a skylight.

Inside, the galleries and programming spaces have wooden floors and a number of multi-media installations created by exhibition designers Ralph Appelbaum Associates.

Large windows at both ends let light into large spaces with circular archival rooms that hold documents of family histories and stories. The side corridors of the building hold a series of narrative exhibitions.

Outside, California-based Hood Design Studio created landscape architecture and artwork that continues the programming and connects the building to its physical environment and to the history of the site.

Collectively called the African Ancestors Memorial Garden, the landscaping features a dune garden and a water feature, laden with symbolic references.

The water feature is a pool of shallow water on top of engravings in stone based on the eighteenth-century Brooks map, a depiction of enslaved people packed tightly together on a slave ship. A perforated, curving brick wall lines one edge of the site.

A wooden walkway leads past the dune garden through a landscape of trees and grasses to a series of stone and wood sculptures and furniture that celebrate "the artistry, craftsmanship, and labor" of African Americans.

The studio included a silver band that traces on the earth the historic boundaries of the wharf and it has been engraved with the names of the other stops that enslaved people may have made during the passage.

"The ground beneath the museum is the artifact of the site," said studio founder Walter Hood.

"As a rich tapestry of water, tabby, grasses, wood, and stone, the hallowed ground and landscape spaces offer contemplation, celebration, and fraught memories."

The site was originally supposed to be a restaurant, but when construction discovered the history of the site, former Charleston mayor Joseph P Riley Jr purchased the site and initiated planning for the museum in 2000. It has then went through a series of different phases and funding streams.

The museum is set to open to the public 27 June.

Pei Cobb Freed & Partners was founded in 1955 by IM Pei, Eason H Leonard, and Henry N Cobb. The studio has completed a number of iconic projects including the US Bank Tower in Los Angeles.

Other projects that create space to recognize the history of African Americans in the United States include the National Museum of African American History and Culture in Washington DC, which was completed by British-Ghanian architect David Adjaye in 2016.

The photography is by Mike Habat and Sahar Coston-Hardy/Esto.

Project credits:

Design architect: Pei Cobb Freed & Partners; Henry N. Cobb, lead designer; Matteo Milani, lead designer; Hitoshi Maehara, senior design architect
Executive architect: Moody Nolan; Curt Moody, partner in charge; Jonathan Moody, project executive, Bob Larrimer, project manager, Julie Cook, senior project architect
Landscape design: Hood Design Studio
Exhibition design: Ralph Appelbaum Associates
Structural engineering: Guy Nordenson and Associates
M/E/P/FP engineering; Acoustic consulting; communications infrastructure; security consulting; lighting design: Arup
Landscape architect of record: SeamonWhiteside
Construction cost consulting: Venue Consulting
Civil engineering; survey: Forsberg Engineering
Geotechnical & environmental engineering: S&ME
Traffic engineering: Bihl engineering
Code consulting: CCI
Water feature M/E/P: Aqua Design International
Commissioning: Whole Building Systems
Museum planning and implementation: Carolynne Harris Consulting
Lighting design (exhibit spaces): Technical Artistry
Multimedia design and production: Cortina Productions
Construction manager: Turner
Construction management: Brownstone
Exhibit fabrication: Solomon Group
Display case fabrication: Zone Display Cases
AV system integration: Johnson Controls