Black text on a white background.
Black Expo is a fair that exhibits the achievements of black culture, business and industry to the public. It was originally engineered and sponsered by the Southern Christian Leadership Conference (SCLC) in the 1960s. Many cities have hosted Black Expo events.
This button is likely a promotional button for the 1971 Black Expo in Chicago. Larry Shaw, the communication director for SCLC/PUSH (People United to Save Humanity) who advertised and marketed Black Expos in Chicago, was also in charge of the public relations for the movie and sound track of Shaft, the 1971 movie about the suave black private detective John Shaft. "BLACK EXPO IS A BAAAAD MOTHER (SHUT YO' MOUTH)" references the famous tagline in the Grammy/Oscar winning theme song of the movie: "Shaft is a bad mother (Shut your mouth)."