Complex sentence: He was active in the National Unity Association, an anti-discrimination group formed in 1949: at the time, blacks in Dresden and other Ontario towns were regularly refused service in restaurants, barber shops and stores.
Split into simpler sentences: He was active in the National Unity Association, a group formed in 1949 to protest discrimination against the town's black citizens. For years, blacks in Dresden and other Ontario towns were regularly refused service in restaurants, barber shops and stores.