Contributed by David Carrier / Few human developments have been more consequential, in terms of both art history and broader cultural expansion, than the movement of Africans within and out of their own continent. The mammoth exhibition “Project A Black Planet: The Art and Culture of Panafrica,” now at the Art Institute of Chicago in twelve high-ceilinged contemporary galleries, includes more than 350 drawings, paintings, photographs, sculptures, installations, watercolors and prints, but also books, magazines, posters, and record albums, made from the 1920s onward. It’s a lot, but never too much.