Danbury Museum & Historical Society is opening a new exhibit today titled "The Fair That John Built.”  The special exhibit will be up through December of this year and focuses on 1946 through 1981 and John W Leahy’s innovations, additions, and creations. Photographs, many that have not been seen in decades and  some that have never been seen will be on display.  The museum says the exhibit will grow and change over the course of the year and will be accompanied by  special events.