Though at times locally maligned for its police-confounding off-shoots, hip-hop’s historical recognition is long overdue at an institution whose mission is the chronicling of American people and American culture. So we were pleased to see Boing Boing relay the news that the National Museum of American History will establish an exhibit of hip-hop artifacts entitled “Hip-Hop Won’t Stop: The Beat, the Rhymes, the Life” including “photographs, posters, handwritten lyrics, clothing and costumes, videos and interviews…