Jacqueline Trescott says it is the Smithsonian's National Museum of African Art, in Washington, DC:
"So now the museum is the go-to place for contemporary African art in America, both in its galleries and in its research facilities. With the infusion of the Smithsonian money, the library grew from about 3,000 volumes to 30,000. Congress earmarked $440,000 for the acquisition of books over three years. The book collection covers visual arts, history, anthropology, religion, travel and even cookbooks."