The title of “30 Americans” is carefully deferential about the being of its artists. All are African-American, but that’s not stated outright: The show’s philosophy is to allow them to claim their identity as they see fit. There are actually 31 artists, not 30, ranging from the well-known (Jean-Michel Basquiat, Carrie Mae Weems, Kara Walker) to the emerging (Kehinde Wiley, Shinique Smith). The exhibit, which includes 76 paintings, sculptures, drawings, photographs, and videos, is drawn from the collection of Mera and Don Rubell and previously showed at their museum in Miami. Of special note for locals is the inclusion of D.C. native iona rozeal brown’s 2007 work, “Sacrifice #2: It Has to Last,” which re-imagines Tsukioka Yoshitoshi’s 1888 woodblock print “Drowsy: the appearance of a harlot of the Meiji era” in enamel, acrylic, and paper on wood panel.