stringent federal security standards. The cost of construction was limited to $500 million ($ in dollars). The competition criteria specified that the winning design had to respect the history and views of the Washington Monument as well as demonstrate an understanding of the African-American experience. The winning design was required to reflect optimism, spirituality, and joy, but also acknowledge and incorporate "the dark corners" of the African-American experience. The museum design was required to function as a museum, but also be able to host cultural events of various kinds. Hundreds of architects and firms were invited to participate in the design competition. Six firms were chosen as finalists: Devrouax+Purnell and Pei Cobb Freed & Partners Diller Scofidio + Renfro, with KlingStubbins Freelon Adjaye Bond/SmithGroup Foster and Partners/URS Corporation Moody Nolan, with Antoine Predock Moshe Safdie and Associates, with Sulton Campbell Britt & Associates The design submitted by the Freelon Group/Adjaye Associates/Davis Brody Bond won the design competition. The above-ground floors featured an inverted step pyramid surrounded by a bronze architectural scrim, which reflected a crown used in Yoruba culture. Under federal law, the National Capital Planning Commission, the United States Commission of Fine Arts, and the D.C. Historic Preservation Commission all have review and approval rights over construction in the metropolitan D.C. area. As the design went through these agencies for approval, it was slightly revised. The building was moved toward the southern boundary of its plot of land, to give a better view of the Washington Monument from Constitution Avenue. The size of the upper floors were shrunk by 17 percent. Although three upper floors were permitted (instead of just two), the ceiling height of each floor was lowered so that the overall height of the building was lowered. The large, box-like first floor was largely eliminated. Added to the entrance on Constitution Avenue were a pond, garden, and bridge, so that visitors would have to "cross over the water" like slaves did when they came to America. The Smithsonian estimated in February 2012 that museum would to open in 2015. Until then, the museum would occupy a gallery on the second floor of the National Museum of American History. On June 10, 2013, media magnate Oprah Winfrey donated $12 million to the NMAAHC. This was in addition to the $1 million she donated to the museum in 2007. The Smithsonian said it would name the NMAAHC's 350-seat theater